(Adobe)/GIMP (Open Source) or vector tools such as Illustrator (Adobe) and Inkscape ..... Modelling software uses a top down approach because it is the common design ... and thus, a lot of tutorials exploring their application are available.
MASTERTHESIS – BRUFACE – ULB/VUB
TOOL FOR AUGMENTED PARAMETRIC BUILDING INFORMATION MODELLING FOR TRANSFORMABLE BUILDINGS Francois DENIS
MASTER THESIS SUBMITTED UNDER THE SUPERVISION OF PROF. NIELS DE TEMMERMAN (RESEARCH); ARANZAZU GALAN GONZALEZ, JONAS LINDEKENS, LAURENT NEY, STÉPHANE MEYRANT AND THIERRY BERLEYMONT (DESIGN), ADVISOR: WALDO GALLE IN ORDER TO BE AWARDED THE MASTER’S DEGREE IN ARCHITECTURAL ENGINEERING
ACADEMIC YEAR 2013-2014
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS AKNOW LEDGEMENTS I would like to express my deepest gratitude to my research promoter Prof. Niels De Temmerman and advisor Waldo Galle for their constant interest and availability during this year but also for their precious advices and feedbacks. For their continuous guidance and useful remarks, my gratitude also goes to the professors who accompanied me through the design studios: Aranzazu Galan Gonzalez, Jonas Lindekens, Laurent Ney, Stéphane Meyrant and Thierry Berleymont. I take this opportunity to record my sincere gratitude to the professors and members of the faculty who allowed the Bruface program to take place. The opportunity of sharing knowledge and experience with students having another background was rewarding. I also would like to thank the Dynamo team and specially Ian Keough to provide such a useful tool as an “open source” software, allowing researchers, students and designers all over the world to benefit from its features and contribute to its development. Finally, I would like to thank my family, friends and classmates for their great support during this intensive year. A special thanks comes to Audrey Kintziger who was present during the last moments of my work and without whom finishing in time would have been difficult.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS TABLE OF CONTENT
AKNOWLEDGEMENTS .................................................................................................................. I ABSTRACT (ENGLISH)................................................................................................................... V ABSTRACT (FRENCH)................................................................................................................... VI ABSTRACT (DUTCH) ................................................................................................................... VII DEFINITION OF SPECIFIC TERMS ............................................................................................... VIII REVIT INTERFACE DESCRIPTION.................................................................................................. IX DYNAMO INTERFACE DESCRIPTION ............................................................................................. X CHAPTER 1:
INTRODUCTION ................................................................................................. 1
I.
Computer in architecture ......................................................................................................................... 1
II.
Transformable Architecture ..................................................................................................................... 2
CHAPTER 2: I.
STATE OF THE ART ............................................................................................. 4
Parametric Design and Scripting Cultures ................................................................................................ 4 Scripting and Algorithmic ........................................................................................................................... 5 a “True” Scripting ..................................................................................................................................... 5 b Architect versus Software Engineer ...................................................................................................... 5 c Visual programming .............................................................................................................................. 6 B. advantages and drawbacks of PD .............................................................................................................. 9 A.
II.
Building Information Modelling and data management......................................................................... 10 Software ................................................................................................................................................... 10 a AutoCAD Architecture (Autodesk), the BIM transition ........................................................................ 10 b Archicad (Graphisoft) and Revit (Autodesk), BIM standardization...................................................... 11 B. Data Management ................................................................................................................................... 12 C. Advantages and drawbacks oF BIM ......................................................................................................... 13 A.
CHAPTER 3:
PROBLEM STATEMENT .................................................................................... 14
I.
benefits of Advanced Parametric Building Information Modeling .......................................................... 14
II.
presentation of the Work process .......................................................................................................... 16 A. Literature and software learning ............................................................................................................. 16 B. Development of a working methodology ................................................................................................ 17 ii | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS Transposition to the Tool ......................................................................................................................... 17 Presentation of the Software and the Tool ......................................................................................... 17 i. Building Information Modeling: Revit ............................................................................................. 17 ii. Parametric Design: Revit and Dynamo ............................................................................................ 18 b Main issues of the transposition ......................................................................................................... 19 D. Application to design ............................................................................................................................... 19
C.
a
CHAPTER 4:
SOFTWARE EXPLORATION AND DISCUSSION ................................................... 20
I.
Revit interface and working process ...................................................................................................... 20 A. Project Management ............................................................................................................................... 20 B. Family Creation ........................................................................................................................................ 21 a Type and Instance parameters ............................................................................................................ 22
II.
Dynamo ................................................................................................................................................. 22 A. Nodes, wires and Ports ............................................................................................................................ 24 B. Software Dependent Version ................................................................................................................... 24 C. Standalone Version .................................................................................................................................. 25
III.
Scripting Into Bim possibilities and limitations ...................................................................................... 25 A. BIM and PD integration, the ambitions ................................................................................................... 25 B. Dynamo and Revit what are the limitations?........................................................................................... 26 C. Practical examples ................................................................................................................................... 27
CHAPTER 5:
LITERATURE STUDY AND PRELIMINARY GUIDELINES ....................................... 30
I.
Revit ...................................................................................................................................................... 30 A. Family Creation (BIMstore bible, 2012) ................................................................................................... 30 a Hosting families ................................................................................................................................... 30 b Level Of detail ...................................................................................................................................... 33 c Element Visibility ................................................................................................................................. 33 d Nesting family ...................................................................................................................................... 34 e Family Name ........................................................................................................................................ 35 f Information and Data creation ............................................................................................................ 36 g Virtual Prototyping and testing ........................................................................................................... 37 h Additional comments .......................................................................................................................... 37
II.
Dynamo ................................................................................................................................................. 39 A. Issues and possible mistakes ................................................................................................................... 39 B. Interface and connection to Revit............................................................................................................ 39
III.
Integrated Approach .............................................................................................................................. 40 a Top Down or Bottom up ...................................................................................................................... 40 b Driving parameter................................................................................................................................ 41
IV.
Hierarchy into design ......................................................................................................................... 41
CHAPTER 6:
CASE STUDIES, DISCUSSION AND REAPPRAISAL OF THE GUIDELINES............... 43 iii | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS I. A. B. C. II.
Case Studies and Discussion................................................................................................................... 43 Perforated panels design (Annex 3) ........................................................................................................ 43 Randomized module combination tool (Annex 4) ................................................................................... 46 Panel subdivision tool (Annex 5) ............................................................................................................. 47
Reappraisal and completion of the guidelines based on the case studies .............................................. 49 A. Additional Software Combination Guidelines .......................................................................................... 49 B. Integrated Approach to Augmented Parametric Building Information modelling: Simplexity ................ 50 C. Framework For Hierarchy Into BIM Scripting .......................................................................................... 51 D. Perspective On Designing with Augmented PARAMETRIC BUILDING Information Modelling: The Importance Of Boundary Conditions ................................................................................................................ 52
CHAPTER 7:
CONCLUSIONS AND REMARKS ON FUTURE DEVELOPMENTS .......................... 53
I.
Added Value During Construction Phases .............................................................................................. 53 A. Conceptual phase..................................................................................................................................... 53 B. Elaborated Design phase ......................................................................................................................... 54 C. Production Phase ..................................................................................................................................... 54 D. Use and Refurbishment of the Building ................................................................................................... 54
II.
Added Value And Possible Improvements Into Revit and Dynamo ........................................................ 54
III.
Better Informed Design and Designer .................................................................................................... 55
IV.
Further Developments ....................................................................................................................... 56
BIBLIOGRAPHY........................................................................................................................... 58 ANNEX 1: STUDENT SURVEY: DESIGN APPROACHES AND COMPUTER USE IN THE DESIGN STUDIO ......................................................................................................................................... I ANNEX 2: PARAMETRIC TWISTED TOWER .................................................................................. X ANNEX 3: PERFORATED PANEL ................................................................................................... XI ANNEX 4: MODULE CONFIGURATION TOOL .............................................................................. XII ANNEX 5: PANEL SUBDIVISION TOOL........................................................................................ XIII ANNEX 6: FAMILY CONTENT CREATION WORKFLOW (BASED ON BIMSTORE BIBLE):................ XIV
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS ABSTRACT (ENGLISH) In past times, the architects and the designers had their imagination and their sketches as only tools to create and represent their projects. Since the invention and the development of computers, computer aided drawings/design tools had been introduced and used by many designers has representation tool. However, those tools are working as a “virtual” drawing table were one can represent his idea through lines, surfaces or volumes. With the development of three dimensional tools for NASA and aeronautics, the idea of having a tool that use defined objects instead of lines slowly came through. Thereby, the software became able to store data and “understand” the model as well as represent it. This is the beginning of Building Information Modelling (BIM), a kind of software as well as a process, on which the model relies on data. However, the developments in computer science and its democratization also generated another movement of designers that used computer code to generate a shape or a model. Instead of using a pen to represent his design, the designer had to script the mathematical relations that were defining its shape. With time, the scripting interface became easier and new ways of scripting such as visual programming had been developed. The main concept of Parametric Design (PD) was to define geometries through scripting. On one hand, Transformable architectures or conceptual shapes are generally designed using a Parametric Design process that allows to model the way they are moving, adapting, rotating or to optimize a shape. But on the other hand, the industry is in constant need of information that complement the drawings of the project. Therefore, Building Information Modelling use is increasing and even becomes mandatory for public works (United Kingdom, USA). However, BIM and PD appear to be quite different in their process and use. Thereby, there is a need to establish a working methodology that would allow the designer to benefit from PD, BIM and also from the added value of their combination. During this thesis, Dynamo is used to bring Parametric Design into the whole Building Information Modelling process in order to enhance the benefits of this combination as well as the limitations. Some practical guidelines, as well as some methodological information on how to share information from BIM to PD, are also provided. The concept of integrated approach which consist in thinking the design, the construction and thus the “virtual” construction as a whole, would allow to manage those process. Indeed, the designer has to develop his project in the virtual environment as he was virtually building it within the tool. Thereby, components and sub-components should be developed and their relationships, or the way they are connected, should be designed. This integrated approach also lead to a kind of hierarchy into design that the designer has to respect in order to improve the potential of his model and his tool as well as his design (design to dismantle, 4D-design). The combination of PD and BIM could lead to better informed design on which the information embedded into the software is not only use to identify elements or give information about the material but also to help the designer in taking decisions or consider alternatives. The true added value of the combination would be at all the stages of the conception, elaboration and refurbishment of the building. Key words: BIM, PD, visual programming, architectural software, design methodology, computation.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS ABSTRACT (FRENCH) Par le passé, les architectes et designers n’avaient comme seul outil, pour développer et représenter leurs projets, que leur imagination et leurs dessins. Depuis l’invention et le développement des ordinateurs, des outils de conception assistée par ordinateur ont été introduits et utilisés par de nombreux utilisateurs comme moyen de représentation. Cependant, ces outils ne fonctionnent que comme des tables à dessin « virtuelles » où l’on représente ses idées au travers de lignes, surfaces ou volumétries. Avec le développement de logiciels tridimensionnels pour la NASA et le domaine de l’aéronautique, l’idée, permettant d’avoir un logiciel capable de stocker des données et de « comprendre » la maquette numérique autant que de la représenter, se développa. Ceci est le point de départ du « Building Information Modelling » (BIM) qui est à la fois un type de logiciel et un processus dans lequel le modèle numérique du bâtiment tient compte de feuilles de données, mais aussi d’une représentation graphique. Les développements dans l’informatique permettent à d’autres designers d’utiliser des codes informatiques pour générer des formes. Plutôt que d’utiliser un crayon pour représenter leur design, ces designers devaient créer des « scripts » transposant les relations mathématiques qui régissent leur design. Avec le temps, l’interface de « Scripting » devint de plus en plus facile à utiliser et de nouvelles façons de coder comme le « visual programming » furent développées. Le principal concept du Design Paramétrique (PD) était donc de définir des géométries à l’aide d’un codage. D’une part, les architectures transformables ou les formes conceptuelles sont généralement créées en utilisant le procédé du design paramétrique, permettant de modéliser le mouvement, la rotation, l’adaptation ou même d’optimiser la forme. D’autre part, l’industrie du bâtiment est en besoin constant d’informations qui complètent les différents plans fournis avec le projet. De fait, l’utilisation de logiciels de « Building Information Modelling » augmente de plus en plus et devient même obligatoire dans le cas de travaux publics (Grande-Bretagne, Etats-Unis d’Amérique). Cependant, « BIM » et « PD » apparaissent bien différents dans leur procédé et leur utilisation. Il y a donc un besoin d’établir une méthode de travail permettant de bénéficier au mieux de ces logiciels mais également de la valeur ajoutée par leur combinaison. Pour ce mémoire, Dynamo est utilisé pour incorporer le design paramétrique au sein de l’environnement du « BIM ». Le but de cette intégration est de mettre en exergue tant les bénéfices de cette combinaison que ses limitations. Des lignes de conduites et une information sur la méthodologie à suivre pour partager des informations entre le « BIM » et le « PD » seront également fournies. Le concept de l’approche intégrée qui consiste à penser la conception, la construction mais aussi la construction « virtuelle » du projet comme un tout, pourrait permettre de gérer ces deux processus. Le designer doit donc développer son projet dans l’environnement virtuel comme s’il était littéralement en train de le construire au sein du logiciel. Les composants et sous-composants qui constituent le projet devraient être développés. De plus, leurs relations et leur moyen d’accrochage devraient être aussi élaborés. Cette approche intégrée amène également une sorte de hiérarchisation du projet et de ses composants. La combinaison du « PD » et du « BIM » pourrait amener à un design mieux informé dans lequel toutes les informations contenues dans le projet ne sont pas uniquement utilisées pour identifier les éléments mais bien comme aide à la conception, à la prise de décision ou permettre d’envisager differentes alternatives. La vraie valeur ajoutée par la combinaison de ces deux outils sera donc présente tant à la conception qu’à l’élaboration du projet ou à sa rénovation. Mots clefs : BIM, PD, visual programming, logiciel architectural, méthodologie de conception.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS ABSTRACT (DUTCH) In het verleden hadden architecten en ontwerpers enkel hun verbeelding en schetsen als hulpmiddel om hun ontwerpen tot stand te brengen en voor te stellen. Sinds de uitvinding en de ontwikkeling van computers en ‘computer aided design’ programma’s, gebruiken vele ontwerpers deze nieuwe technieken om hun ontwerpen te visualiseren. Deze technieken zijn als het ware ‘virtuele’ tekentafels waarbij ideeën kunnen voorgesteld worden door middel van lijnen, vlakken en volumes. Met de ontwikkeling van driedimensionale softwaremodellen voor de ruimtevaartsector in het algemeen en NASA in het bijzonder ontstond ook het idee om een ontwerpinstrument voor de bouwsector te ontwikkelen waarbij objecten als elementen worden gedefinieerd en niet als simpele lijnen. Bij deze ontwikkeling werd het voor de software mogelijk om data op te slaan en het model zowel te “begrijpen” als voor te stellen. Dit was het begin van “Building Information Modelling” (BIM), een software en werkwijze waarbij het numerieke model van het gebouw gebaseerd is op databases. Gelijktijdig laten nieuwe ontwikkelingen in de informatica ontwerpers toe vormen te genereren aan de hand van geprogrammeerde codes. In plaats van hun ontwerp te visualiseren met potlood en papier, schrijven ze een “script” dat de wiskundige relaties die hun ontwerp beheert, omzet in een driedimensionaal model. Het opzet van Parametrisch Ontwerp (PD) is precies het definiëren van bepaalde geometrieën aan de hand van een codering. Langzaamaan wordt de interface van het “scripting” makkelijker en makkelijker en ontstaan er nieuwe programmeermethoden zoals “visual programming”. Enerzijds creëren ontwerpers steeds vaker transformeerbare gebouwen of architectuur met een zogenaamde vrije vormgeving. Parametrisch ontwerpen laat toe om de vorm,beweging, rotatie en andere aanpassingen van deze gebouwen te modelleren en zelfs te optimaliseren. Anderzijds is de bouwwereld constant op zoek naar informatie die de verschillende plannen van een ontwerp aanvult en vervolledigt. Om die reden wordt “Building Information Modelling” steeds populairder en is het zelfs verplicht geworden het te gebruiken bij openbare werken in Groot-Britannië en de Verenigde Staten. Niettegenstaande blijken “BIM” en “PD” toch zeer verschillend in hun proces en gebruik. Er is dus de nood om een methode te ontwikkelen die van de voordelen van beide methoden kan genieten, maar ook beide kan combineren. Voor dit eindwerk is Dynamo gebruikt om het parametrisch ontwerp in te bouwen in de BIM-omgeving. Het doel van deze integratie is om zowel de voordelen als de beperkingen van deze combinatie in kaart te brengen en richtlijnen over de te volgen methodiek om informatie uit te wisselen tussen “BIM” en “PD” aan te bieden. Het idee van de geïntegreerde werkwijze laat toe om het ontwerp te bedenken, visualiseren, maar ook het “virtueel” te bouwen in zijn geheel. De ontwerper moet bijgevolg zijn ontwerp ontwikkelen in een virtuele omgeving en zal letterlijk bezig zijn om het te bouwen in de software. De onderdelen waaruit het ontwerp bestaat moeten ontwikkeld worden, eveneens als hun onderlinge verhoudingen en de manier van verbinden van verschillende onderdelen. Deze manier van werken brengt ook een zeker hiërarchie teweeg binnen het project en zijn onderdelen. De integratie van PD en BIM kan leiden tot een ontwerp waarbij meer en gerichter informatie is opgenomen in het model. Deze kan niet enkel kan dienen als hulpmiddel bij het ontwerpen, maar ook om bij het onderhoud of de renovatie meerdere opties binnen voor te stellen en te evalueren. De echte toegevoegde waarde van de combinatie van deze twee tools zal dus zijn weerslag hebben op zowel het ontwerp, de uitwerking als de verdere levensduur van een project. Sleutelwoorden: Building Information Modelling (BIM), Parametric Design (PD), Visual programming, Architecturale software, Ontwerpmethode
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS DEFINITION OF SPECIFIC TERMS AEC AEC means Architecture, Engineering and Construction. Thus, AEC objects or software are objects/software linked to the fields of architecture, engineering and construction. BIM objects are considered as AEC objects. ALGORITHM: Process or a set of rules, usually one expressed in algebraic notation, now used especially in computing, machine, translation and linguistics. BIM OR BUILDING INFORMATION MODELLING: The National Building Information Model Standard Project Committee has the following definition: Building Information Modeling (BIM) is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its lifecycle; defined as existing from earliest conception to demolition (National BIM Standard) CAD OR COMPUTER-AIDED DESIGN/DRAWING: The use of computer programs and systems to design detailed two- or three-dimensional models of physical objects, such as mechanical parts, buildings, and molecules (Collins English Dictionnary). DYNAMO: Dynamo is a visual programming environment for Building Information Modeling. It extends the parametric capabilities of Revit and Vasari with the data and logic environment of a graphical algorithm editor (Dynamobim.org). MEP: Mechanical, Electrical and Plumbing PARAMETER: Variable to which other variable are related by means of parametric equations (Sakamoto & Ferré, 2008, p.119). PD OR PARAMETRIC DESIGN: Process based not on fixed metric quantities but on consistent relationships between objects allowing changes in a single element to propagate throughout the system (Marco Vanucci in (Sakamoto & Ferré, 2008, p.119)). Possibility to establish intricate system of relations between different objects and their properties fusing the hierarchy between parts and whole (Marco Vanucci in (Sakamoto & Ferré, 2008, p.119)). HVAC Heating, ventilation and air conditioning. VISUAL PROGRAMING: Way of write code using a graphical interface. The elaborate writing code is wholly or partly replaced with the visual metaphor of connecting small blocks of independent functionality into a whole system or procedure (Boeykens & Neuckermans, 2009) SCRIPTING: Capability offered by almost all design software packages that allows the user to adapt, customize or completely reconfigure software around their own predilections and mods of working . Generally the script is a written text in a computer language dependent on the language used during coding of the software (Burry, 2011).
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS REVIT INTERFACE DESCRIPTION
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS DYNAMO INTERFACE DESCRIPTION
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS CHAPTER 1: INTRODUCTION
I.
COMPUTER IN ARCHITECTURE
The design process for architects and engineers has evolved a lot since the first drawings with feather and ink. In the end of the 20th century, computer-aided design (CAD) software became commonly used by designers in order to improve the quality, the ease of use and the speed of the representation process. As it has been for all the technologies, the turn of the century involved many developments in the field of computer aided design and modelling. Many researches had been facilitated by the fast evolution of technologies and calculation / modelling capacities of personal computers. Since then, designers use packages of software not only for representation purpose but also during the conceptual design process. Some programs, like Rhino (with a plug-in such as Grasshopper), allow them to literally play with a structure’s geometry in order to find an optimal solution. Such a design approach allows the user to vary different parameters and design structures that were difficult to develop before such as transformable structures. Indeed, while designing transformable or adaptable buildings, a lot of aspects are variable. For instance, the shape of the building could change during use or simply according to seasons. Therefore, Transformable Structures with adaptable components ask for components that could change or evolve such as folding shading systems on façades or modules that can be removed or added. Indeed, the Parametric Design (PD) approach allows the user to determine components, shapes and assemblies through the use of parameters and mathematical relations. The software improves the ease of development of complex structures and allows creating different variants. Those programs clearly help the designer in the conception process. However, it seems that they are not sufficient in order to produce complete documents. Thus, most of time their use is reduced to the early stage of a design, before entering in the CAD software. Nowadays, it seems also that the new capacities of computers allow them to go further into detail while not only playing with geometry but also with data. This thought is the beginning of the Building Information Modelling (BIM) concept or strategy. In this kind of programs, the designer is not only drawing plans, views, elevations and a 3D model. He is virtually building the whole project within the software while determining all the different particularities or characteristics of his design. Obviously, those particularities would be integrated into the software as mathematical parameters or relations. BIM software is not only a modelling tool but also a database management tool (Howell & Batcheler, 2005). Thus, it produces and saves data into a single file (Figure 1).
Figure 1: What is behind BIM? BIM is more about data than 3D modelling 1
1
Figure taken from http://www.kuiper.nl/content/news/bim_kc2.jpg
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS II. TRANSFORMABLE ARCHITECTURE As the computer use in architecture evolved, the architecture itself has also changed. On one hand, the construction industry like other industries, such as automotive industry, is more and more trying to develop mass production and prefabrication. On the other hand, the concept of sustainability is also taken into account more and more often. This evolution led designers to find new ways of designing. Developing an architecture that fits perfectly those concepts is more than just transforming a normal building into another. In addition to that, our rapidly evolving society is in need of buildings that can also evolve or be upgraded easily. In fact, some well-known concept of modern architecture, such as the “plan libre” of Le Corbusier, could be define as a way of designing a transformable buildings. As another example, in 1924, the Schröder house was designed in a way that the upper floor could be reconfigured each day with partition walls. Thus, we see that even if the concept of transformable house seems to be quite recent, its seeds are deeply linked to the history of architecture. In the book “The Transformable House” (Bell & Godwin, 2000), the concept of transformability is defined by: • • •
Use of modular systems to facilitate construction and planning Development of complex devices for modifying and customizing architectural space on a day-to-day basis. Integration of technology into the home
The global concept of transformable architecture could be easily linked to the definition of architecture itself. In the book “The transformable house” by Jonathan Bell and Sally Godwin, the architecture is defined as the power to revolutionize social conventions through the addition of the rigid floor plan. In the case of a company building, it has to fit with comfort and organization of the employees. However, in a family house, it is the separation and the fragmentation of the domestic sphere that is sought. The house is then designed in order to fit with the conventional family. But today, what is a conventional family? What is the best office design? Does our way of living would be the same in thirty years? As an answer to these questions we can compare today’s architecture and ways of living with the buildings thirty years before. Our buildings did not have computers, domotic or ventilation systems. People were used to have a big dining room separated from the kitchen and the living room, where today we prefer open kitchens, directly linked with the living room. According to Jonathan Bell and Sally Godwin, the craze for the use of “Do It Yourself” interior crafting methods in conventional houses is directly due to an inappropriate design of the space. Basically, people are trying to “transform” their house into an hybridization that fits entirely or not to their needs. In addition to this evolving ways of living, nowadays architecture has to answer to new questions linked to prefabrication, mass production, sustainability and respect of nature. Thus, transformability is met not only in sliding, moving or rotating walls but also in new concepts such as design for disassembly, kinetic façades responding to the sun or simply through kit-of-part building system. However, transformability could also be seen in more exotic structures with inflatable beams or deployable structures. Thus, transformability means ability to change or respond to change. Transformable architectures are thus, moving, adaptable, changing and dismantling architecture. The key point of those structures are connections because the transformable character of such a structure is mainly depending on their boundary conditions. Another reason why the concept of transformability is more and more developed is also due to the increasing cost per square meter of living space. People cannot afford to buy the 300 square meter apartment that they would ideally like; instead, they buy one 100 square meter, and they try to live in it 2|Page
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS as it has 300 square meter (Helen Castle in the “Transformable House”) (Bell & Godwin, 2000). Thus, a simple door could transform a space just because its open, semi-open or closed state could drastically change the room. This form of transformability is quite easy to use but should be taken into account during the early design stage. In transformable house, Helen Castle present a building designed by Mark Guard where the doors are not used only to close a room but to fully determine the space. Actually, the door is acting as a rotating panel that determines, according to its opening angle, different boundaries. Thus, those simple elements called doors have the ability, if well used, to shape the space and make it live: “They are not forming the boundaries of the room; they are forming something within the room that you look beyond and around” Mark Guard (Bell & Godwin, 2000) As a conclusion on this introduction, I would like to emphasize the fact that the architecture is built in a living environment and thus, its relation with its context is quite different according to the season or the hour of the day. The environment influences the buildings as well as they compose it. Duralumin said: “Dwellings are (also) environment – controlling machines” Richard Buckminster Fuller (Bell & Godwin, 2000) Thus, we should probably develop our building in order to fit its environmental as well as social context today but also in the future or, at least, allow him to be upgraded easily. If building is an environment-controlling machine, it should be able to adapt when needed (change of use or way of living) like a machine is upgraded when its task evolves.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS CHAPTER 2: STATE OF THE ART
I.
PARAMETRIC DESIGN AND SCRIPTING CULTURES
In order to have preliminary information about the use of PD and BIM software during the BRUFACE master program, a survey had been set. According to the Master 1 and Master 2 students, parametric design could be explained in few words by: “Easy to make shape/form analysis and to see interactions between different parameters”, “finding an optimal solution”, “You can study very easily the influence of various parameters on your design, because all the other elements of the building will automatically be affected by this change and rearranged in a new configurations” or “multiple configurations/Designs” (Design Approach and Computer use in the design studio Survey – Annex 1) As a remark, I would like to enhance that 100% of the answers of the question: “Which software would you use in order to produce parametric objects/design?” were Rhino with Grasshopper (which we learned at the university). But this also shows that none of the students knew another parametric design tool which could also generate confusions about the definition of parametric design. How can we separate the features provided by parametric design and the features provided by the specific tool “Grasshopper”? Another common confusion exists between parametric design, which is the concept, and visual programming, which is a tool allowing to use parametric design. And, according to Marco Vanucci in “From Control To Design” (Sakamoto & Ferré, 2008), parametric design could be defined as: “Process based not on fixed metric quantities but on consistent relationships between objects allowing changes in a single element to propagate corresponding changes throughout the system.” Marco Vanucci in (Sakamoto & Ferré, 2008, p.119) But an adapted definition of parametric design is considered in the rest of this thesis: possibility to create and develop complex system of relations between different components/parts/objects inheriting properties through connections with other parts and the whole. This definition highlight the fact that PD is not only used to produce a geometry for an unique project but to find a way to define a process allowing to produce various possibilities. This clearly shows a new relation between technology and architectural production. The computer is not only a representative tool anymore but it interferes with and contribute fully to the design process. Furthermore, this approach allowed a lot of developments in the field of scripting such as algorithmic design which allows complex forms from simple iterative methods. “Parametric models offer another type of play and design process based around multiplicity of scalar parameters, but it never resolves what parameters are necessary for architecture” Michael Meredith in (Sakamoto & Ferré, 2008) In contrast to the approach of determining all the variables, the designer has to keep in mind that the reality is far more complex than just few parameters and thus, he would have to make choices. Furthermore, it is clear that all existing parameters are not easily quantifiable. All connections or relationships are not fully geometric or sometimes even impossible to define on a simple way. The designer as the person in charge of the project has the responsibility to create boundary conditions which are developed to fit to the reality or to avoid a “too randomized” solution. 4|Page
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS A. SCRIPTING AND ALGORITHMIC “Scripting as an approach to computational design, offers access to whole new ways of exploring design, but design remains always the core” Mark Burry (Burry, 2011) Without entering into detail, it is clear that we have to define and explain what scripting and algorithmic are: it will help us to identify the state of the art in this branch merging architectural design and computer science. As there are many ways of designing, there are many ways of scripting. However, we could divide the scripting population in several groups according to their workflow. For instance, some designer only use mathematical programming language in order to produce conceptual shapes while other prefer to draw everything by CAD. There are also in-between-people who clearly understand the benefits of parametric design but do not want to code everything from scratch. According to those affinities, many scripting techniques or cultures had been developed (Burry, 2011). As the non-scripting population of designer is considered as the classical population, only the scripting cultures will be developed in this part. Into this field, we could divide scripting into two main stream. The first is the one I call “True Scripting” because those who use this kind of programming systems are clearly developing skills and knowledge from the computer science world (Burry, 2011),(Sakamoto & Ferré, 2008) & (Jabi,2013). The Second one is the visual programming scripting which is still scripting but as simplified as possible in order to allow designer to benefits from main of its advantages without being a programmer. The main question that divides those two worlds is “Does an architect has to be a software engineer?” a
“True” Scripting
“If the parametric is a technique for the holistic control and manipulation of design objects at all scales from part to whole, the algorithmic is a method of generation, producing complex forms and structures based on simple component rules” (Sakamoto & Ferré, 2008,p.4) During this thesis, I will make the distinction between the written scripting which will be defined as “true” scripting and visual programming which is also a kind of scripting with a graphical interface. By true scripting, I mean a scripting interface without a graphical interface. Thus, the scripts developed by the designers are text-based scripts. It means that the syntax or the language used by the programmer will totally change the script but its structure coming from an algorithm would be the same in different languages (Jabi, 2013). The idea here is not to debate whether or not a language or scripting technique is better than another. However, knowing the advantages of the “True” scripting would enormously help to imagine the benefits of using it into a “classical” working environment (CAD, BIM). Because of its computer oriented workflow, true scripting is rarely used for the whole design of a building. Often, it is used to give an answer to a particular problem such as a surface generation or subdivision or a mathematically-based relation between geometries (Burry, 2011). b
Architect versus Software Engineer
“Because scripting is effectively a computing program overlay, the tool user (designer) becomes the new toolmaker (software engineer)” (Burry,2011) It is clear that the architect or an architectural engineer major role is not to code and develop tools with programming languages. In Belgian architectural schools, the students in architecture have computer science applied to architecture but do not have programming lessons. It means that they learned CAD tools with 2D or 3D environment, image manipulation tools such as Photoshop (Adobe)/GIMP (Open Source) or vector tools such as Illustrator (Adobe) and Inkscape (Open Source). 5|Page
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS In an architectural engineering school, some students have the opportunity to learn programming. At ULB, in the second and the third year of bachelor, students learn to code Python (few years before C++). Even if designers are not programmers, this learning is quite important because it helps students to decompose a problem in a clear structure. This process of decomposition of a problem/task into boundary conditions is also encountered during the design process. Belgian researchers from Katholieke Universiteit Leuven clearly state that the curriculum of architects, and thus architectural engineers, would benefit from programming lessons (Boeykens & Neuckermans, 2009). Furthermore, a basic knowledge in programming would allow designers to produce parametric objects. Those objects are geometry based objects but, instead of having fixed dimensional parameters, the user of this object could change parameters while he is using it. As an example, the designer could work with windows that are placed on walls and, after a while, he thinks that the windows should be bigger. Thus, instead of replacing the old windows, he can just change their size’s parameters. When one is trying to develop such elements in BIM software, one needs to code those parametric relations through excel files. It is clear that more complex components would need a lot of excel scripting. Thereby, a knowledge in programming would allow the user to master his time and to simplify the relations between parameters, providing efficient components that will not freeze the computer. Fortunately, there is an alternative to written code which is called visual programming. It helps designers to have a better understanding of the world of coding and scripting, without being a computer scientist. c
Visual programming
The concept of visual programming could be compared to the concept of graphical algorithm. An algorithm is a step by step procedure for solving a problem with a graphical representation following the rules of algorithmic. This kind of representation is widely used even in field that does not deal with computer science at all. Its main advantage is that it easily and rapidly represent a process or solution method with a diagram. In such a diagram, the steps are often divided with a question which as two possible answers: Yes or No. According to the answer, the path that we will have to follow in the algorithm would be different. In this simplistic example below (Figure 2), are described the tasks executed in case of risk management issues. Even if we use the algorithmic conventions in order to draw the different boxes, an uninformed user has the ability to understand the process. That is the key feature of visual programming and that is also why their community grows fast.
Figure 2: Flow chart or Algorithm of Risk Management. 2 2
Picture taken from: Mawdesley, M., & Askew, W. (19971996). Risk identification, analysis and response. Planning and controlling construction projects: the best laid plans-- (p. 193). Essex, England: Longman
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS This kind of algorithm representations is widely used because they are easily understandable. Even if this representation is not very complex, algorithm with variable parameters and specific questions are not as easy to understand as flow chart algorithms. We could say that this is the starting point of the visual programming. Thus, visual programming is a simplified programming system using a graphical interface wherein elements are representing functions. An extensive description is provided by Stefan Boeykens and Herman Neuckermans (2009) in the quote below: “The elaborate writing code is wholly or partly replaced with the visual metaphor of connecting small blocks of independent functionality into a whole system or procedure. Through the application of Graphical User Interface items or widgets, designers can even add interaction to their design, allowing exploration of different alternatives through the modification of parameters controlled by sliders, check boxes or other widgets. Their visual approach assists in creating a functional solution, while at the same time being less dependent on strict syntax and more easily adaptable during the development” (Boeykens & Neuckermans, 2009) The picture below (Figure 3) shows an example of an early visual programming interface called GRaIL – Graphical Input Language, developed in 1968 by Alan Kay which clearly looks like a visual programming interface. In addition to that, it was capable of recognizing handwriting and thus, the programmer has only to draw his algorithm by hand. This is certainly not the first working visual programming and we could say that Algorithmic are the true ancestor of Visual Programming but it shows clearly that the idea of a simplified way of translating information from the reality to the computer is not completely new.
Figure 3: GRaIL – Graphical Input Language, 1968, Alan Kay 3
During the BRUFACE program, students of Architectural Engineering had the opportunity to learn a visual programming tool called “Grasshopper” during the course of “Parametric Design for Transformable structures”. This course was in fact the aggregate of two important notions: • •
3
Parametric Design Transformable structures
Picture taken from: (Kron, Lopez Compo, 2011)
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS The reason why those two notions were merged together is because parametric design is one of the best way to develop transformable structures using a computer. It is also because the design of transformable structures need a kind of parametric design because it is about structures that could respond to change and a way to implement a change in a computer design is to modify a parameter. During the course, students learn to use Grasshopper which is a visual programming interface for Rhino. As AutoCAD is the standard of the CAD format and is well known and used all over the world in different industries, Grasshopper seems to be the standard way of producing parametric design in a visual programming environment. This software is a plugin of the well-known nubs modelling system: Rhino. If we had to simplify the way Grasshopper is working, it is basically launching Rhino functions through a graphical interface embedded into a programming environment. Its strength are mainly dependent on the functions implemented in Rhino and on the concept of visual programming. Rhino, as a 3D modelling tool, allows many ways of producing conceptual shapes. And this, associated with the structure provided by the scripting, allowed a lot of people to use it. With this popularity and the easiness to improve scripts, many plugins for Grasshopper were rapidly provided such as calculations or formfinding scripts. This tool benefits from a flourishing popularity. The main problem of Grasshopper is exactly its strength of the early stages: Rhino. Actually, Grasshopper’s main features are dependent on the features provided by Rhino. It appears that visual programming would be more powerful if its parameters would be linked to the components used in the design itself. Thus, it would not be used only to generate shapes and geometrical relations but could also help to truly define a component and extract information from it allowing the software to “understand” the design as a combination and not just as a geometrical addition of 3D objects. As an example, a project made in Rhino using Grasshopper is just an assembly of lines, curves, surfaces and volumes (Figure 4). Thus, windows are not different from walls because the software only see them as a group of lines. But if the software was BIM-based, it will make the distinction between windows and walls and can thus calculate the percentage of glazed surface on the whole project. There are projects, as VisualArq 4 that try to implement a BIM interface into Rhino. However, it should be stated that Rhino is a 3D modelling tool and not a drawing orientated platform. Thus, even if BIM objects and functionalities were implemented into this software it would not be able to produce easily the same amount of documents as true CAD or BIM systems. It does however not mean that Grasshopper is not a good tool. Actually, this is one of the best parametric design tool because it has the easiness of a visual programming interface with the possibility to increase its features through scripting/coding (python language for instance). It means that the user can use the pre-coded blocks in order to develop his conceptual form and, if needed, can code part of his work in order to have a more “out-of-the-box” configuration.
Figure 4: Grasshopper script that produce various building configurations using boxes. This script was developed during academic year 2012-2013 “Parametric Design and Transformable structures” 4
VisualARQ is a precise, intuitive and free-form architectural software for Rhino - http://www.visualarq.com/
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS B. ADVANTAGES AND DRAWBACKS OF PD In a traditional medium, any change in the model requires erasure and remodeling whether it is with pad and pen or via CAD but, in a parametric model, every entity (points, lines,…) have links between their location in the software’s database and their visualization via monitor. Thus, modifying a part of the model would generate a global update of the whole design. In few words, we could say that a typical CAD approach allows to create easily lots of geometries but it is difficult to make changes where a PD approach create geometry based on relationships and thus, change is fully integrated in the global approach. This is mainly why parametric design tools such as Grasshopper are widely used as design tools by architects (Tedeshi, 2011). In addition to provide interconnected relations between objects, Parametric Design also facilitates automation. As an example, the serpentine gallery pavilion (Figure 5 & Figure 6) designed by Alvaro Siza, Eduardo Souto de Moura and Cecil Balmond had been created using parametric design. The use of parametric design allowed the automation of the creation of all the wooden sub-components (Sakamoto & Ferré, 2008). In a world with 3D printing, CNC machines and at the time of “mass customization” parametric design use could increase constantly.
Figure 5: drawing showing the main concepts of the serpentine gallery pavilion 5
Figure 6: Picture of the Serpentine Gallery Pavilion 6
A key point in the favor of parametric design, or at least visual programming, is its intuitive interface and the real-time feedback. They usually work in a simple interface where the user needs to connect blocks. While having understood the main concepts, this kind of software does not have a lot of different functions. They are always using the same kind of tools (list management, addition, multiplication) but their final result could differ a lot. For example, in AutoCAD creating a hexagon or changing the layer properties are two different functions which are executed using different processes. But, in Grasshopper, all the functions consist in receiving a parameter as an input (geometry, number, and list), execute the command and then give another parameter as an output. The process is always the same. Even if there are new functions, they will follow the same principle. However, the main issue while working with parametric design is that the software is only playing with geometry. As a result, that software does not fully “understand” the problem and is not able to detect problems or uncertainties which are specific to the object. In a script, two geometry can easily intersect each other or two elements could move without friction even if they touch each other. While working with transformable structures, such as scissor structures, a 3D computer model could easily work even if its exact replica in the real world is not perfectly working. The limitation of parametric design in traditional systems, such as Grasshopper, is that it is almost only geometry based and thus, there is few links with reality. In order to avoid those kind of problems, the designer has to find parameters that will
5 6
Picture taken from (Sakamoto & Ferré, 2008, p.44) Picture taken from http://www.serpentinegalleries.org/
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS help him to determine if a model is acceptable. This thesis will tackle this problem by combining PD and BIM. Another problem with parametric design is simply due to its principle. It is used as a conceptual tool and not as a representational tool. Thus, a designer who likes his creation has to export/import his design into different software, such as AutoCAD, in order to produce plan, sections and elevations. If the design was not an iterative process with tries and errors, it would not be a big issue. But when the designer has to change even a small parameters into his original design, he will have to reproduce the “export/import” phase and thus, lose one of the key issue of parametric design: real-time feedback. To conclude, Parametric Design provides many geometrical features, brings automation and allows the designer to produce different alternatives using a real-time feedback. However, the components used are limited to their geometrical representation and the 3D model does not benefit from the list management features of PD. In addition to that, producing presentation plans involves to use another software.
II. BUILDING INFORMATION MODELLING AND DATA MANAGEMENT As the concept of Building Information Modelling comes directly from the software called BIM software, the process and the implementation of BIM will be quite dependent on the chosen software. Thus, two kinds of BIM software have been tested. The first one represented by AutoCAD is a hybridization of CAD and BIM. It is an evolution of CAD that is able to manage BIM objects. But the second kind of software is composed of full BIM programs that are not based on CAD systems anymore. Thus, a small distinction between those two processes and their limitations is provided in the next section. A. SOFTWARE a
AutoCAD Architecture (Autodesk), the BIM transition
Presentation and functionalities: This software is also known as Architectural Desktop (ADT). The concept of this software is to add AEC (Architecture, Engineering and Construction) objects to an AutoCAD bottom layer. The AEC objects are parametric components or subparts which have different properties define through parameters: material or color. The basic functionalities of ADT are the functionalities within AutoCAD. In fact, the aim of AutoCAD architecture was to provide a BIM compatible interface for AutoCAD users. Thus, functions, as integrated models with fully updated sections, are present but are not fully supported by ADT. For instance, changes that are made in plan are not directly made in sections, unless the user asks the software to update sections. For that reason, ADT is more a transitional solution than a real BIM software. Corresponding (Boeykens & Neuckermans, 2008) to Limitations: • •
•
Lack of connection over different floor levels Complexity to fully configure the display level (It is just an assembly of AutoCAD sheets thus, elements are only made of lines and their appearance is not changing automatically according to the scale). Project navigator is just an index of different AutoCAD files.
These limitations are the reasons why the second category of BIM software is far more efficient and thus, will be used during this thesis.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS b
Archicad (Graphisoft) and Revit (Autodesk), BIM standardization
This thesis will focus on this type of BIM integration because their aim is to have 100% of BIM components while the previous kind of system still allowed lines-only representation. BUILDING INFORMATION MODELLING: The National Building Information Model Standard Project Committee has the following definition: Building Information Modeling (BIM) is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle; defined as existing from earliest conception to demolition (National BIM Standard). BIM software use is increasing constantly and it should be noted that the United Kingdom decided to make the BIM process mandatory in the case of public building. They made this decision based on multiple reasons, the main ones are the increase interoperability, the easiness of data storage and the building/component life management. United Kingdom users see the most value from BIM through (McGraw-Hill Construction, 2009): • • •
Reduced conflicts during construction (70%) Improved collective understanding of design intent (69%) Reduced changes during construction (60%)
In addition to that, it should be noted that the students, while answering to the survey provided in annex 1, described BIM advantages as (Annex 1): “BIM manages digital representation of characteristics of a building during the design and building process: three spatial dimensions, time and cost. - The integration of structure, architectural design and technical data in 1 model. This will lower the amount of mistakes made during the whole design process. - Sharing knowledge with all involved actors in the design of your project and combining everything together “ BIM software are usually bringing four mains features which ensure that they respect the whole BIM process (Figure 7). Main functionalities: •
Visualization: Prototype the building and have a better understanding of its relation with the context. Try and compare different hypothesis.
•
Coordination: Time efficient and reductions of errors.
•
Simulation: Structure, MEP, simulations.
• Figure 7: All the information about the real building are embedded fully within the BIM process. Thus, it can be consulted at any time with any device.
durability
and
Management: Scheduling, cost, construction phases.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS Another key feature of the BIM process is that the improvement of the visualization or coordination and management is not only developed for the computer of the different designers but the project manager has the opportunity to consult directly that information on site with his phone or tablet. Thus, computers are production and visualization tools, while phones and tablets are mobilevisualization tools. Currently, research projects about augmented reality are developed in order to use the camera of the tablet and its localization to display in real-time the 3D model of the project (smartreality.co, Laing O’Rourke 3D BIM Augmented Reality). All information that can be collected in a BIM model can be used to observe project construction cost but also operation cost during the lifetime of the building. Even if the building cost is always highlighted, the operation cost during the lifetime of the building is far more significant. The use of BIM in architectural design and construction should be stimulated because it ensures an increase of the interoperability, efficient data storage and the life management of the building/components (McGraw-Hill Construction, 2009). B. DATA MANAGEMENT In the field of BIM, the core of the process is the management and sharing of large databases, integrated models, and relationships build between predefined components recognizable as architectural or technical objects. BIM allows not only to store the information about the project but also to use it in order to produce “material quantity take off” or construction phase schedules. Thus, it is able to create/store/manage and use the data embedded in the project and not only for the production of plan/views. The data management also allows BIM to filter the information provided to the user according to his needs. Thus, HVAC engineer interface will not show windows and non-bearing walls but will show the ventilation systems while the structural engineer needs to see the structure of the building but does not need information about the insulation of the walls. BIM process is able to interact and fully manage its embedded information in order to fulfill the requirements of its user. Saying that BIM does not allow parametric design would be totally wrong (Boeykens, July 2012). However, the parametric power of BIM is sometimes lost in its interface. PD with graphic interface, where changing parameters are controlled by different panels and windows, is nice and easy but sometimes, when the amount of parameters is huge, using script to vary them is far more easier and faster.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS C. ADVANTAGES AND DRAWBACKS OF BIM In order to show the main advantages of BIM, I will compare it to the traditional CAD system. In CAD systems, you are drawing on the computer as you were by hand but on a BIM interface you are placing components in relations to each other. Thus, when you need a drawing, the software is able to extract and project the information needed into a plan, elevation or section (Figure 8 & Figure 9).
Figure 8: The main difference between BIM and CAD. BIM is a 3D model with different views while CAD is only drawn plans 7
Figure 9: A change in a view generates an update of the whole model
In addition to that, BIM is a data management interface which allows to store information within its interface. The model is not only a 3D model but a bunch of excels files linked to a 3D view. It ensures that all the information about the project is stored inside the project. This will improve the coordination of the building during its construction but also later during its use or in case of refurbishment. Another advantage is the fact that BIM components can be parametric objects defined by parameters. It allows the designer to produce customs elements very easily by simply modifying the generic components provided by their software. The objects can also be quite adaptable. Indeed, their measures can change or the combination of elements such as a window and a wall generates some specific features. However, those parametric objects have also limitations. It is difficult to use data from a part of the project and use it to drive another part. The objects are parametric but making relations between the parameters of different objects is almost impossible. In fact, BIM components are parametric objects. BIM software are using parameters in order to store information or specific information but the placement of objects or their relation to each other are designed to be used in a more static workflow. Thus, there is a need to improve the link between the data embedded into the project and their influence on specific components.
7
Picture taken from http://goolier.com/index.php/2009/05/bim-the-new-cad/
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS CHAPTER 3: PROBLEM STATEMENT
HOW THE INTEGRATION OF BIM AND PD COULD IMPROVE THE WORKFLOW OF THE DESIGN AND MAINTENANCE OF TRANSFORMABLE BUILDINGS.
I.
BENEFITS OF MODELING
ADVANCED
PARAMETRIC
BUILDING
INFORMATION
PD and BIM are two design tools that have proved their usefulness in practice and research during the past few years. Recent research pointed out that both tools are characterized by “Parameters” (Boeykens, 2012, July). Actually, they are more closed to each other than they seem. Both are using intelligent components linked by parameters and mathematical relations and thus, are able to evolve while changing parameters. However, they are different in methodology (Table 1: Summarized Comparison between PD and BIM). While BIM software work with elements and components on which relations and parameters are implemented into datasheets; PD software make relations between different geometries. Table 1: Summarized Comparison between PD and BIM.
Design Software PD Design
Tool
/
Parametric
Key Concept - Geometry: objects are just geometry but the user considers them as walls, insulation or components - Real-time feedback
BIM Building Information Modelling
- Data - Objects or families with different characteristics and understood by the software as components with physical properties
Implementation of - Geometry and relation between them - No “components” with parameters inside them - Easy to change the shape of the design - Definition of components, materials, schedules. - Difficult to change the geometry
Function / Output - Possibility to export the 3D of the design into CAO software - Not a presentation tool. Needs another software to produce plans/sections - All technical drawings are within the BIM database - Plan/sections are produced
Another big difference between those approaches is the design process. Building Information Modelling software uses a top down approach because it is the common design approach commonly taught in architectural schools: the designer has to develop a conceptual mass in a site and after that, goes more and more into details. On the contrary, at least on a theoretical stage, Parametric Design is based on a bottom up process which resembles more the approach of the traditional engineer: first, design details, assemblies and components and later use them to build a whole project. Those approaches are not only different but clearly opposite (Figure 10: Top down versus Bottom up approach). Consequently, even if they use both a parametric approach, they rarely merge (Boeykens, July 2012). However, a complete understanding of those approaches is the bare minimum in order to think about their interoperability. One of the aims of this paper is to provide guidelines in solutions that allow the worlds of BIM and PD to meet. At this moment, the interoperability between software is key factor of improvement particularly into the BIM approach because the file format depends on the program (Howell & Batcheler, 2005). 14 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS
Building Information Modelling/Parametric Design (Conceptual Design) Top Down Approach Develop a building/project and choose materials and components in order to fit to the project Context - Masterplan Project / Shape Bigger Objects / Components Assembled Small Objects / Components Details
Parametric Design using a component approach : Bottom Up Approach First, design of details and assembly and then make a project Figure 10: Top down versus Bottom up approach
Regarding transformable buildings, the integration of Parametric Design in Building Information Modelling should bring new features and would raise the design process to another level. Indeed, the designer would not have to choose between top down or bottom up because both will be supported. This key feature is making this research very unique and relevant. On one hand, PD could improve the development of compatible, resizable and thus, re-usable components by using parameters and mathematical relations in order to align or connect their form and dimensions. On the other hand, BIM could be used to place, connect and assign those components in space and, while considering different states or transformation scenarios, in time. The result of the correlation of those approaches, while integrating PD in BIM, would facilitate the efficiency of practical construction data production that could be used to assess the main advantages of buildings and especially of transformable buildings. The design process could then loop from PD to BIM until the end of the design (Figure 11).
Parametric Design produce the geometry and the different scenarios (deployable and transformable buildings)
Building Information Modelling add materials, properties and components and updates data
Figure 11: Loop Using BIM and PD, as a model for linking the features from PD and BIM
Programs like Autodesk Revit, which are used in practice, include tools for the parametric design of building components called "Families" for example. Those tools benefit of a large user community and thus, a lot of tutorials exploring their application are available. However, that information is almost 15 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS restricted to the modelling of non-generic sub-assemblies. In reaction, this research aims for the development of a new “modelling tool” recommendations for objects, assemblies and a way connecting them with open databases and comprehensive guidelines should be developed. Together they could form the basis for an innovative design methodology.
II. PRESENTATION OF THE W ORK PROCESS Now that the main problem statement as been expressed, the working process used during the research has to be developed. Actually, this research being majorly linked to practical use such as the design approach and building management, there is a constant need of dialog between the theoretical developments made during the research and some practical use of this tool. Thus, the design studio served as a laboratory where I had the opportunity to not only test and check my preliminary conclusions but also find new ones. This loop approach with constant feedbacks from applications had to be structured in order to be useful and prevent from time losses. Thus, the whole working process has been divided into four mains parts: Literature and software learning, development of the method, transposition to the tool and application to the design (Figure 12). Each part will be explained or contextualized below.
•BIM •PD •Comparison •Set Boundaries Chapter 4: Literature and Sofware learning
Chapter 5: Working Methodology and guidelines
•Interaction •Scientific Fundamental Method
•Description •Limitations •Innovation •Improvements
Chapter 6: Application to Design
• Working / Not Working •Efficient? Easy?
Chapter 6: Transposition to the Tool
Chapter 6 :Reappraisal of the guidelines
Figure 12: Summary of the working process used during this master thesis research
A. LITERATURE AND SOFTWARE LEARNING The first part allows to gather information about • • • •
Transformable Architecture, transformability and 4D design Scripting and Parametric design Building information Modelling Specific which had been selected and are presented in (C. Transposition To The Tool) software through tutorials and specialized books or blogs.
The main difficulty was to understand clearly the needs of a tool combining PD and BIM in the case of transformable architecture. In parallel to those researches, another issue was to fully understand how the software works but also how it is structured. Thus, research about the concepts of scripting and parametric design where made. This literature study and software learning is reported in chapters 2 and 4. 16 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS B. DEVELOPMENT OF A WORKING METHODOLOGY The main idea is to develop a methodology which ensure the user to benefit as much as possible from the two worlds. The methodology would work as a hypothesis in a scientific experiment. After that, I will have to design “experiments”/test to prove/refute/improve the whole working process. The developed method would give guidelines in the creation and use of Revit elements in order to make “complete” BIM objects but also in the way we should use the possibilities of the Revit Families parameters to produce parametric components. Furthermore, some rules about shared information between Dynamo and Revit would be provided. Finally, this working methodology will also be applied on the project scale when dealing with components and subcomponents. C. TRANSPOSITION TO THE TOOL The following part will be the transposition of the theoretical guidelines into the computer and practical worlds. The step is almost the same we have in computer science while transposing an algorithm into a coding language. The working methodology proposed would not be completely dependent on the software used, they will explain the optimal situation and the “optimized” workflow. On the opposite, the transposition to the tool will be fully dependent on Dynamo and Revit and their features. The choice of using an existing software instead of making one came from many reasons: • • • • • •
Dynamo seemed to already guarantee a kind of interoperability with Revit and was already linking partly BIM and PD together. Dynamo, as explained in the next part (Presentation of the software and the Tool), is open-source based and thus, could be easily edited or improved by the users. Dynamo is supported by Autodesk which is developing Revit and thus, there is a developer team constantly working on it. BIM is a complex system to implement (3D modelling and datasheets). It is an opportunity to improve the existing tools instead of re-coding a program which already exists. This is also an opportunity to focus on the methodology and on the design process instead on the software coding. a
Presentation of the Software and the Tool i.
Building Information Modeling: Revit
Revit is a relational database with a 3D front end which is detailed in the A3 provided at the beginning of this thesis (A3s: Revit Launcher interface, Revit family interface and Revit project interface). Its entire structure is about relationships allowing alterations of the design intentions, constraints and their implementation in the real building (Figure 13 and A3s). This structure is the reason why it seems possible to combine Revit and a parametric tool in order to produce even more parametric objects. Revit is a complete design suite allowing to produce building information modeling in discipline-specific environment. Thus, interface for Architecture, Structure and Mechanical, Electrical and Plumbing (MEP), as well as a scheduling system or material quantity takeoff, are provided. This complete design suite offered by Autodesk is made for interoperability between the different actors of the construction industry and provides standardized file format in order to allow their use in other tools like in solar or structural analysis.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS
Figure 13: Revit = relational database with a 3D front end
ii. Parametric Design: Revit and Dynamo . Dynamo Dynamo is an open source project for developers and designers to become actively involved in the development of the tool. On its website www.Dynamobim.com it is defined as an “Open source graphical programming for design”. It provides a visual programming environment for Building Information Modeling. Presently, Dynamo extends the parametric capabilities of Revit and Vasari with the data and logic environment of a graphical algorithm editor (A3: Dynamo interface). However, Dynamo is not fully dependent of Revit or Vasari and thus, instead of only providing a visual programming interface, it brings totally new possibilities for design and analysis of building models. One key functionality of Dynamo is simply to allow to change, rapidly and easily, a bunch of data or parameters. Those parameters could be changed directly in Revit but Dynamo is faster and easier and allows those changes without entering into a menu with sub-menu interface. Since the version 0.6.3 Dynamo is also working in a standalone version. However, the aim of this master thesis is to test fully, and bring as much as needed parametric design into the BIM workflow and thus, only the functions provided into the Revit interface will be studied in detail. Dynamo has been chosen because of its interoperability with Revit. This tool is having a constant dialog with Revit and is not only compatible with Revit but almost fully integrated with it. Thus, it can play with geometry but also with Revit elements. This particularity is very important because it means that it can gather information from a part of Revit such as solar vectors and use it to feed another parameter. Actually, since few years, Dynamo is supported by Autodesk. It ensures to this tool long life viability and also increases its development because full-time developers are employed to improve it in addition to the community which is contributing to the project on GitHub.com, the open source development platform. . Revit (family) We have already presented Revit in the part explaining the choice of our BIM software. However, the role of Revit is not only linked with the BIM standards. Revit is already a kind of parametric modeling. It is not fully dependent of a coordinated-based geometry in order to create objects. It uses what Autodesk calls the Revit parametric change engine which allows BIM objects to be linked not only 18 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS by their absolute coordinates but also by their local values and their relations with other objects. In addition to that, it automatically coordinates changes into all the views allowing and data sheets. In order to provide this power of parametric objects, Revit is dependent of intelligent components called families. Those components are 3D geometry linked to spreadsheets with both technical and geometrical information for each component as well as parameters and mathematical relation that link that information. b
Main issues of the transposition
In current discussions on internet platforms and in publications, it seems that architectural designers that want to adopt PD or BIM are confronted to two major challenges while using parametric design in the architectural process (Kron & Lopez Compo, 2011): • •
How to rationalize a form into a buildable elements. How to create geometry frameworks to represent design requirements.
These two challenges are linked to a bigger issue: Transform ideas into reality. During a discussion at the Autodesk University 2011, the Zach Kron proposed to use two methods: •
•
“Pre-rationalizing” based on requirements. This concept clearly links the bottom-up process and considers all the requirements or components at the early stage as boundaries for the development of the design. As the requirements has been used till the beginning, there is no need to work to modify the project at the end of the design in order to fit the norms or the components needed. “Post-rationalizing” in manageable elements. This approach is clearly linked to a component sub-component approach but they are only introduced after having developed a shape or a concept. Thus, the designer starts with a conceptual project and rationalizes it later with components. While trying to simplify the concept as much as possible, we could say it is a kind of Top-down approach.
Those key issues are generally problematic at the moment when the construction of the building begins. However, with Parametric Design and Building Information Modeling software, since the early stage of the design process, the designer would have to find a way to produce his freeform shape with mathematical relations or segment his building into components. Basically, those issues of “prerationalizing” or “Post-rationalizing” are not created by the use of those tool but have to be used prematurely. This will allow the designer to think his design as whole in a fully integrated approach. This concept will be developed later in the section entitled “Integrated Approach” (chapter 5 and 6) of this thesis. D. APPLICATION TO DESIGN Although, several cases studies are tested in order to relate this research as much as possible to the real design challenges. Testing the proposed configurations on the scale of a real project enhances the collected information and helps to determine, whether or not, they are efficient in a design workflow. Therefore, the whole design part that comes together with this research (Portfolio) has been made only with Revit and Dynamo. As a challenge, I decided to work without any other architectural or construction tool (CAD, modelling, simulation or analyzing). This means that all the documents will be produced in a BIM environment. It does not mean that all the objects used will be fully BIM or fully parametric but it clearly states that it is possible to work during the whole design process in a BIM interface. Furthermore, the use of parametric and non-parametric objects shows that the coexistence of those two worlds into the BIM interface is possible. The insights I developed during the design part are integrated implicitly in all sections of this thesis. 19 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS CHAPTER 4: SOFTW ARE EXPLORATION AND DISCUSSION
I.
REVIT INTERFACE AND W ORKING PROCESS
Even if Revit is one program with one main feature, its interface and thus, its workflow is divided in two particular parts (Figure 14 & A3: Revit launcher interface). This division is not just a graphical division but a clear distinction between two scales of a same project. At the beginning of the software exploration, it was expected that the project management interface would be the most interesting and powerful part of Revit but it appeared that the key features of BIM come from the family creation interface.
Figure 14: Revit 2015 welcome page and the two different interface
A. PROJECT MANAGEMENT The project management interface is the place where the architectural project will be virtually build using BIM components (Figure 15 & A3: Revit project interface). The main principle of this interface is to allow the user to build the project in three virtual dimensions while adding other information, such as relations between components, schedules information or construction phases. This interface does not allow to produce new elements or components but only to use and to manage them. Even if this could be seen as a drawback for Revit, this is a key issue of the way the BIM process is embedded into Revit. Actually, it means that in order to use components, the designer has to define their geometry, their use and their embedded information and thus, composing the whole project in three dimensional visualization as well as in information and data gathering. In addition to that, this interface is subdivided according to the field of work. Consequently, an architecture–only user will not use the panel “MEP” or “STRUCTURE” because the tools have been sorted in different panels according to their use. However, it is possible to open a project made into the “Architectural template” in a MEP project environment and Revit will automatically change the visibility options according to the field. Basically all the fields have the same core “interface” with few visibility options that differ. In addition to composing the project, the project management environment allows to visualize the building in a three-dimensional model as well as launching renderings. Moreover, key BIM functions, as the ability to produce schedules or Material quantity takeoff (filtered by material for instance), are also fully integrated into the project management interface. In few words, this interface holds all the data needed during the construction and links it to a geometry which is represented through different views.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS The core information is the data, while the 3D, plan and sections are just “filters” that select or decompose part of the data in order to provide a “view”.
Figure 15: Revit 2015 Project Interface while working on the VUB student residence
B. FAMILY CREATION As explained in the introduction of this chapter, the family interface is maybe used less by students or new Revit users. While exploring it, it was found that this is the place where Parametric Design and BIM could merge. This interface (Figure 16 & A3: Revit family interface) is made in order to produce new components for Revit. Thus, it has the advantage of allowing to play with geometry only and add data afterwards. Moreover, it allows also to drive geometrical relations with numerical parameters.
Figure 16: Revit 2015 family creation interface while creating the structural module of the VUB residence
The parametric features from the family interface is mainly provided by the concept of “reference point”, “reference plane” and thus, all the “reference” geometry based on points and planes. In fact, those “reference” planes and points allow the family to use relative coordinates instead of absolute coordinates. Thus, instead of defining points at a coordinate (x;y), the points are put at a distance (x;y)
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS from each other. It means that the second point is virtually attached to the first one and, if the “master” point moves, the other will also move. a
Type and Instance parameters
While creating or using a family, one has to use two different kinds of parameters. The distinction between two kinds of parameters is needed into Revit because they are working at two different scale. Actually, Type and Instance parameters are only different into the BIM process but, in term of parameters, are working on the same principle. Thus, those parameters can be defined as mathematical relations or as a combination of other parameters but their key difference is link to the concept of family. A Type parameter is a parameter that is the same for “one type of family”. Thus, a “door 90x200” family in Revit has fixed dimensions that would be different in a similar type “door 120x200” for example. Generally, material, sub-components and general dimensions are the same in families which have the same type. In walls, the different layers are defined as Type parameters because all the walls of the same type should have the same composition. But an instance parameter is a parameter which is specific for one object and thus, could be different for two identical family types. Doors, for example, could be placed at different heights from the floor. Sometimes, due to a difference of height between two rooms, there is a need for a step. But the Revit Family “door” is the same if it is used at a different height or level. As another example, the length of a wall is also an Instance parameter because, while building a wall composed of 15cm concrete and 10cm of insulation, its length is not dependent on its composition/type but clearly depend on a specific object of the type “concrete + insulation”. Type and Instance parameters are key issues while working on parametric objects. Indeed, a bad definition of Type and Instance parameters could lead to limitations within the model.
II. DYNAMO “I would like to think that in the next 10 years we will have succeeded, and will have a new conceptual environment for creative thinking and without the need for scripting. If all we have achieved is to replace drawing with typing then we have achieved nothing.” John Frazer in (Burry ,2011, p.64) Dynamo, as explained in the previous chapter, is an “Open source graphical programming for design” (DynamoBIM.org). It is on many points similar to “Grasshopper” but also clearly different in its concept. Dynamo has been created by Ian Keough, an American designer who was working on different architectural offices. His role was to model complex shapes or architectural choices into the computer. While working on software like Revit, he reached their “parametric” modelling limit and had to develop small add-ons that could allow to add a particular feature. Being aware of project like “Grasshopper”, he began coding his own open source plugin Dynamo. As Zach Kron explained on a google hangout entitled “Enhanced practice introduction to Dynamo”, “Dynamo learned lessons from Grasshopper and other tools”. The Dynamo developing team was clearly aware of the limitations of other visual programming interface and they tried to develop a new tool keeping the core of the concept but also bringing new possibilities. If we had to synthesize Dynamo’s features in few lines we could say that it does two main tasks (Sgambelluri, 2014): • •
Produces and manages its geometry within its own interface using parametric relationships Is able to read and writes to and from external Databases 22 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS A quick, easy and accurate way to compare Dynamo to Grasshopper, the “standard” of visual programming, is to define which software they are based on. Grasshopper, which is based on Rhino, is a “Visual Programming for Computer Aided Design software” while Dynamo is a “Visual Programming for Building Information Modelling”. So, even if their interfaces are quite similar, their core processing and features are distinct because they are based on different materials. Another key difference is that Dynamo has been developed in order to be partly standalone and partly software dependent. It means that some of its features are just Revit features embedded in its visual programming interface (as it is the case for Grasshopper and Rhino) and the other are fully dependent on Dynamo. Dynamo has its own visualization interface. Due to the fast development of the tool and its potential (Figure 17), Autodesk decided to buy it and take in charge its development while keeping it open source. This allowed to improve the correlation between Revit and Dynamo but keeping it open source also allowed to continue the development of exclusive features. Actually, during its development, Dynamo is more and more working conjointly with Revit while also being more independent on particular features. At the beginning, Dynamo was only working on top of Revit but the last version (0.7) can also work as a fully standalone version. And thus, only the features that needs Revit information are disabled but geometrical relations or list managements are fully functional. In few words, Dynamo is not only a visual programming interface for Revit but it clearly rewires Revit allowing to transmit parameters from a part of the model to another (moving data sources) while adding new geometrical and list management features.
Figure 17: Dynamo taxonomy showing the amount of nodes provided 8
In addition to rewire Revit’s functionality, the Dynamo team is working constantly on its interoperability with other languages or platforms. Thus, python language is supported since the early version of development and the version 0.7 has been fully recoded based on the design script language. This opens new opportunities but can also generate difficulties because scripts made in the earlier version are not compatible with the new version. The developers decided to re-code the whole Dynamo in order to have a clean base for the next developments. However, this is not as problematic as it seems because Dynamo 0.6.3 (old core) and 0.7 (new core) can be both installed in a computer allowing designers to finish their work in 0.6.3 while developing the new scripts on the improved workflow. Even if the distinction between the software dependent core and the standalone core is not as clear as the Revit interface is, those two different parts will be explained separately because they both provide different features. However, it should be highlighted that while working into Dynamo (within Revit), the user will not see and experience the difference between the standalone and the software dependent nodes.
8
Picture taken from: http://autodeskvasari.com/profiles/blogs/Dynamo-thus-far
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS
A. NODES, WIRES AND PORTS Before explaining in detail the main functionalities provided by Dynamo and its interface, a few concepts specific to visual programming and to Dynamo should be explained. As we explained during the presentation of the state of the art, parametric design and visual programming are linked to the world and to computer sciences. Their aim is mainly to help non-coder to script useful tools easily. Thus, they have to allow the user to code by using a more user friendly interface. Dynamo’s team decided to simply use visual programming as a translation tool and thus, they defined the following elements: •
Node: The node is the equivalent of a “function” or a “command” in computer science. They are displayed as yellow boxes with a brown title. It is a group of instructions that use parameters as input and produce other parameters as output. The picture below (Figure 18) represent an example of a homemade node generally called “custom node” by Dynamo users. Its title is “1st floor module XYZ creation” reflects the aim of the node which has been scripted for one of the case study presented in the chapter 6 that is called “Randomized module configurations”
•
Wire: The wire is the link between two nodes. It is literally linking an output of a node into an input of another. Its role is to pass the parameter from a node to another. The wires are attached to the ports of the nodes and a wire can transmit a parameter, a list of parameter and even a list of list of parameters.
•
Port: The port is the place where the wires are connected to the nodes. Generally, an input port receives one wire while an output port can be connected as much as needed. This means that a node (function) can only receive one group of input in order to produce one group of output but the outputs can be used in different places. Limiting the amount of inputwire is a good way of avoiding errors. Thus, if the user has to link to list to the input port, he has to join them and clearly select which one will be the first or the second one.
If nodes are not connected and thus not used, they are colored in grey instead of yellow. If there is an error (wrong input or problem while executing the command), the node becomes red.
Figure 18: Description of Dynamo nodes, wires and ports
B. SOFTWARE DEPENDENT VERSION The software dependent operability of Dynamo is probably the most interesting while dealing with the interactions between BIM and PD because all the nodes which are Revit-dependent are the ones that allow data sharing between Dynamo and Revit. Actually, Dynamo’s ability to create and read to and from database is the key feature that allows this data sharing. Thus, Dynamo can read information from Revit and modify them. Dynamo can also read information on a part of the Revit file (such as sun 24 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS paths) and use it to drive Revit family parameters (such as sizes of openings, as evaluated in chapter 6 in the “perforated panel creation” script). Thus, Dynamo is literally rewiring Revit and works as a data delivery system. Even when Dynamo is launched as a Revit plug-in, its own geometrical, list management and mathematical functionalities are enabled. Thus, Revit and Dynamo are working side by side with their own functionalities while in a Grasshopper/Rhino workflow, Grasshopper is taking the lead and then, the designer has to bake his geometry in order to use it into Rhino. Here, Dynamo and Revit can produce geometry or elements (Revit geometry creation is limited in the project interface) and Revit can use Dynamo objects without having to bake them and vice versa. In addition to its own list management and mathematical functionalities, Dynamo also provides a python script node that allows the designer to write python scripts directly within Dynamo. This way, he can use visual programming as well as the “true scripting”. C. STANDALONE VERSION As explained in the introduction of this subchapter, Dynamo is also working in a standalone version. Its features are mainly linked to mathematical, geometrical and list management functionalities. Dynamo is able to produce a shape by lofting, rotating or sweep curves without the help of any other software. It also integrates new languages such as DesignScript 9 language. This standalone version is not directly linked to the aim of this master thesis because Dynamo alone is not integrating BIM and PD functionalities. However, the fact that Dynamo is able to produce geometrical elements within its own interface allow the user to load elements directly into the Revit project interface, avoiding the problem of switching interfaces each time a shape has to be modified. Another key issue is that having a standalone version helps the programmer to develop Dynamo for other software. At Autodesk, they are currently trying to link Dynamo to Maya, a 3D computer graphic software used in the production of games and special effects. This means that the tool will not be limited to Revit and thus, could benefit from other applications and could facilitate interoperability between different programs.
III. SCRIPTING INTO BIM POSSIBILITIES AND LIMITATIONS In the previous chapter, Revit, Dynamo and their features were introduced separately. However, the aim of this thesis is to analyze the combination of these tools in order to bring new features or functionalities. This chapter will thus develop the possibilities but also the limitations of the integration of BIM and PD. A. BIM AND PD INTEGRATION, THE AMBITIONS The main ideas behind implementing scripting techniques into BIM are to improve the design approach but also to allow automatized workflow or analysis through scripting. The power of such techniques is well known in the field of contextual design where the designer needs a way to interact rapidly and easily with his model in order to change the shape without having to redraw everything. A well know example is the “Centre Pompidou Metz” museum designed by Shigerun Ban and Jean Gastines were the wooden laths composing the structure of the membrane are fully dependent on the geometry of the design. However, in fields such as energy or light analysis, where parametric and scripting tools are emerging for many years, their usefulness has been proven for changing orientation, time or localization. We could say that the limitations of scripting are clearly linked to the limitations of 9
DesignScript is a programming language for exploratory design and analysis. http://designscript.ning.com/
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS mathematics. All the shapes or the relations that could be linked to a mathematical relations could be implemented. However, the translation of the relations into mathematical concepts could be more difficult depending on their complexity. Producing shapes or geometry with scripting is always achievable. The real question is thus: Is it always needed? Does it always worth it? The aim of putting BIM and PD together is to allow scripting to take place into the BIM interface without limiting its features (Boeykens, July 2012). The user has to be able to choose if he needs or not to script for a particular part of his design. If introducing visual programming into BIM induces that the whole project has to be produced with Dynamo in order to be parametric, this would however leads to problems because the user will miss many features of BIM itself. But if the scripting can be used when needed and can be linked with the “standard” BIM process, this will induce a clear improvement of the BIM workflow because it will add new features while removing nothing to its main core. In the same scope, the tool should provide visual programming but also allow some other kind of written scripting such as python. And thus a good tool will allow the user to play with its different scripting/Designing methods and select the best solution for his particular design. B. DYNAMO AND REVIT WHAT ARE THE LIMITATIONS? Hosting elements on other elements is an important feature in the BIM process and specifically in Revit, closely related to a tradition conceptualization of building: windows are always hosted by walls, skylights by roofs and walls by levels. In the current 0.6.3 version of Dynamo, Revit family placement is limited on XYZ and level, face or point hosting system while functionality as wall hosting or family hosting are available in Revit and not implemented in Dynamo. On a practical point of view it means that windows placement using Dynamo is not yet possible by family placement. However, those features are still available in Revit and the use of Dynamo in another part of the process does not reduce the power of the native Revit features. On the contrary of imported elements created with another software or plugin, the Revit’s features that are not integrated into Dynamo can still be used into the Revit interface. For instance a wall produced in Dynamo is still a Revit wall where we can attach a window within the Revit interface even if the hosting by wall is not embedded into Dynamo. It means that each software keeps its own limits but, combining the tools and selecting the one that fits a particular task and use it, allow the global workflow to be drastically improved. For example, Dynamo is far more easier on a conceptual point of view, because sliders and changing parameters can easily generate a new shape, while Revit, is rather rigid. However, in specific cases, it is more feasible to place elements one by one because of their specificity or their relations with the site and thus, it would take long to make useless script. Although previous limitations were found and points of attention revealed, it should be highlighted that both programs are made to “talk” to each other. Thus, elements created in Dynamo are directly created in Revit and there is no need to bake or change something. If a script has been made and needs a face to generate a paneling system, even if we close the file, Revit and Dynamo will remember their relation.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS C. PRACTICAL EXAMPLES Before providing scripts applied directly to the design studio, a few scripts are shown to enhance the potential of the combination of BIM and PD through visual programming. The scripts presented below will show some features such as automation, free form generation, placing of Revit families and volume generation through mathematical relations. All these conceptual tools are explained below and a complete explanation of particular scripts and a further representation of their results will be provided into corresponding annexes. •
Free-form generation
As it has been discovered in the “Student Survey” provided in annex 1, many designers use a different software for the conceptual design than for the production of documents. Sketchup or other intuitive 3D modeler are often used by students because it is easy and fast to change the shape. Thus, they think that AutoCAD and Revit are not as efficient as Sketchup during the early stage of the project. It is true that the conceptual design phase in Revit is not as intuitive as it is in Sketchup or FormIt (Ipad Modeller developed by Autodesk). However, while working on the family interface, the user has all the necessary tools to produce conceptual shapes (i.e. reference points, curves and planes). In addition to the traditional functions, Dynamo would provide an algorithmic combining geometrical and mathematical information (i.e. shape and height). In addition to that, the real-time visual feedback is particularly interesting during the conceptual design because it allows the designer to manage and visualize many changes at once. The shape presented in the picture below has been made using Dynamo (Figure 19). The coordinates of the external spiral are based on the Fibonacci sequences. The script then creates other curves in order to allow Revit to loft the surface along those curves. This shape is fully driven and created into Dynamo but at the end of the process, the lofting is made into Revit (but launched from Dynamo).
Figure 19: Generation of a free form based on the Fibonacci series
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS •
Tower based on polygon generation (Annex 2)
As it was discussed in the beginning of this chapter, the major improvement provided by the combination of Revit and Dynamo concerns the optimization possibilities during the conceptual design. Creating a parametric “twisted tower” (with main parameters: height, twist angle) based on a parametric polygon (number of edges, dimensions) does not take more than creating one tower based on a polygon. This example shows clearly the easiness provided by the Dynamo workflow within the Revit interface (Figure 20).
Figure 20: Generation of a nested polygon tower
•
Auto level creation
This small example shows that visual programming will not only add new features to Revit but also help to simplify the automation of a specific task. While designing on Revit, the user has to define different levels into the software. Those levels have to be created one by one and it is not a problem while working on a small building. However, when designers have to work on towers, an automated level creation would clearly improve the workflow. Actually, a Revit plugin provides this feature but this Dynamo script showed that it can be made in a small amount of time (Figure 21).
Figure 21: level creator script and its result within the Revit interface
Furthermore, the level creator also allows the user to literally drive the height of the levels. A tower, which is created using those levels, is thus directly driven by this script. We could imagine a tower that is composed of 25 levels of offices and 15 levels of dwellings. The designer starts with a 5 meters 28 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS from floor to floor height in the offices part and a 3m50 in the dwellings. After having designed more in detail his project, he determined that a perfect floor to floor height for the offices is 4m20. Thus, he can actually use the level generator to change the offset between each level of offices and update his whole project (Figure 22).
Figure 22: Combination of Level Generator, "twisted tower" generator and Revit tools: Wall on face and Floor on Level
•
Components or adaptive component placement (Dynamo: Visual Programming For Design)
Finally, this example taken from the Dynamo 0.6.3 tutorial shows how the combination of Dynamo and Revit brings new features to the BIM process. A truss family has been made into the family interface of Revit using an adaptive component template. It means that the family is place and controlled by reference points. In this case the truss is defined through three points (two feet and the top of the truss). Once this family had been made and saved, Dynamo is used to place it along three curves (Figure 23). In order to allow this placement, curve division and list management features provided by Dynamo are used. This example shows clearly the potential beneath the conjoint use of BIM and PD: a combination of small scripts.
Figure 23: Revit family place using Dynamo. A typical example of the integration of BIM and PD.
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Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS CHAPTER 5: LITERATURE STUDY AND PRELIMINARY GUIDELINES The aim of this sub-chapter is to provide practical as well as theoretical guidelines that will help to improve the BIM-PD process. Some of these guidelines are not particular to the combination of BIM and PD but respecting them would allow to improve their integration. Some of those guidelines are clearly particular to Revit because the BIM process nowadays is different according to the software used (even if the main principle are common). However, the majority of the concepts could be easily transposable into another software while taking into account their specificities.
I.
REVIT A. FAMILY CREATION (BIMSTORE BIBLE, 2012)
In order to enhance the relations and the interoperability between Revit and Dynamo, it seems clear that the creation of new elements in Revit, if they are made to be use also with Dynamo, should be quite different than the basic family creation. This whole section is based on the recommendations of the “BIMstore bible”. This book written by bimstore.com is providing guidelines to manufacturers in order to allow them to produce “efficient” BIM families. BIMstore teams are currently developing different BIMstore bibles according to the BIM software and its features. The Revit bible is already written and is based on the British standards as well as the Autodesk recommendations. However, those guidelines are very specific to BIM itself and are written for the “standard” industry which is not necessary “transformable buildings” and PD is not considered. Some remarks, modifications or improvements of those guidelines will be discussed during this chapter. a
Hosting families
Since the beginning of the creation of a new family, the designer has to know clearly what would be the final use of its component. As in real life it seems clear that a table is not made in the same way as a door even if they are in the same material, in a BIM software families are divided and subdivided in categories. The first distinction would be between the generic families and the specific manufacture content. In general, generic families are far more parametric and allow more changes while manufacture families have fixed dimensions or materials depending on the manufacturer. While developing a transformable buildings it seems legit that the smaller subcomponents are manufactured families (with factual dimensions, materials and geometries that are possible to produce in factory) while their custom made assembly would clearly use a generic template. Even if this distinction is quite important while making new elements, it is not the key problem in transformable building. The quality of a family is generated not only from the quality of its geometry but above all by the quality of its relation with the whole project. For instance, we could draw the best door and windows systems from a graphical point of view. However, if we forget to define strong relations with other elements they would not be usable. One of those relations is hosting: for example, a door or a window needs to be attached on a wall. Thus, while placing it, the wall will be perforated in order to allow the component to be placed. Technically, there are at least seven different ways of hosting elements. As a guide to select the best hosting type, all seven types are discussed below: •
Point-based hosting: The classical way of placing a component is by attaching it to a point. This kind of hosting is the one used in a classical CAD interface. In Revit, point based elements are not common and efficient because, in reality, an object is never attached to a floating point but on a surface or on a curve. However, multiple points based hosted elements are very powerful in particular cases such as the case study about “adaptive component placement” presented in the previous chapter. This kind of hosting has to be chosen only if the type of geometry on which the point is attached 30 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS has no importance (face, curve, edge or point). Thus, point-based hosting is also used for conceptual designs. Standards objects have to be placed or attached on faces (i.e. object on a table, paints on a wall). •
Curve or edge-based hosting: Basically, when managing adaptive components (i.e. components that are define through reference points instead of fixed points and thus, having a non-fixed shape), a hosting curve is very useful. However, as point-based hosting, curve-based hosting is very useful while making conceptual designs or inside the creation of a family. But at a scale of the project itself, families does not need to be attached to curves because, in reality, a curve does not really have a meaning as it is not a 3D element. The only way that curves have a meaning in reality is the edges or intersections of faces.
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Face-based hosting: This is the first practically useful hosting system in the case of families. As families are objects/components, a face-based family is an object that needs to be attached to a face. This could be the case of a computer or a glass that needs a horizontal plane. The advantage of a face-based hosting is that it works on all kinds of faces. A wall, a floor, a door or a ceiling are basically composed of faces and thus, are working hosts. Some objects are limited to horizontal or vertical hosts such as our glass or computer are not attached to the walls. In practice, face hosting is used when the components are attached to the external face of an element (wall, door) but, in the case were elements are attached directly to the core or structure of elements, another hosting system has to be chosen. In general, only small objects or lights are face-based.
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Wall-based hosting: Objects that are hosted to the wall could be seen as a particularity of face-based hosting systems. However, this is not fully true because they can have special features. First, a wall is a 3D BIM object with a composition that creates layers of different materials. Second, those layers do not have the same importance: some of them are structural or have thermal insulation properties. Thus, their interaction with objects that are attached to them is not simply a “face” connection. Objects should rely on the structure of the wall and not only on its external face. Finally, due to the reality of the object “wall”, when a wall is hosting a window or a door, the wall as to be opened at the exact place of the window/door. This is why wall-based hosting is not the same as simple face-hosting.
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Floor-based hosting: Tables, sofas, fridges, shower and bath are objects that are generally attached to the ground floor. In fact, all the components called in real life “objects” are face-based or floor-based. A floor based system is almost equivalent to the classical face-based system. It does not have the same complexity than the wall-based system and only provides some practical features. For instance, placing a table in Revit is very fast. You only have to click on the place you want it and it finds automatically the right floor (according to the view you are working on). If tables were using facebased, the user would have to, first, select the face on which the table would be place and, after that, select its location on the face. In general, we could say that furniture are floor-based objects.
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Ceiling-based hosting: Technical systems, for instance, sometimes need to be attached to the ceilings. This hosting system has the same characteristics than the floor-based systems. The only difference is that an object placed using the floor hosting system will be visible on the classical floor plan, even though a ceiling hosted object will be higher than the view and will thus, be visible only on a ceiling plan view.
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Level-based hosting or two-level-based hosting: This is also a very special kind of hosting because, in reality, it does not have a real meaning. This kind of hosting system is more dependent on the way the software works than on real facts. In Revit, all the floor plan views are delimited through levels. Those levels have a given height. In order to have an efficient workflow, elements, such as walls, are defined as level hosted. It means that, in general, a wall begin at a certain level and finishes at another one. While building virtually the model, walls can be made on 60 meters height without the needs of floors to be attached to. 31 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS It should be noted that floors are also level-based systems and thus, all the objects attached to a floor will move with the levels. Levels are virtual limits allowing the model to be divided on a vertical way. It should be noticed that in Revit hosting systems, objects does not necessary have to fully touch the host. For instance, the back of the toilet is generally facing the wall without touching it. Thus, we could see the toilet unit as a wall-based objects even if it does not reach it because of its technical sewing systems. All those hosting systems could be adapted using an offset which allows the user to have more flexible objects still respecting the conventional rules. As some of the hosting systems does not have a real interest while making families, they will not be used frequently outside a conceptual design interface. For the most usable hosting systems, it is possible to pre-load those characteristics as templates when creating a new family. BIMstore provides four main templates for hosted objects: wall, floor, face and ceiling hosted templates. The other kinds of hosting, being more dependent on the kind of family you would create, will be embedded directly into them: a generic wall, column or floor template is level-based. Those specific families are the system families and are easily recognizable into the Revit interface, while the classical objects are used under the tool “component”. Basically, it means that Revit has special families: door, window, wall, floor and curtain walls, which have special features and other components (Figure 24). Those system families also have their own template files. Thus, creating a door is not just creating an object with a wall-based template but it has its own door template with special relations, such as the generation of the hole on the attached wall.
Figure 24: example of function that load a specific kind of family within Revit Architectural Interface
In theory, new objects would not need to be directly level-based and, if they should, they will inherit their level-based behavior from the component they are hosted on. If an object is attached on a wall, which is attached on a level, thus changing the level will change the wall and all to object attached to it. For those reasons, the advice sounds like: take some time to select the hosting type carefully and then use the appropriate template. For instance, I tried to develop a system were the windows were attached to prefabricated panels. But, in Revit, windows are only wall based. This means that it is not possible to attach those windows to something different than a wall. There are three solutions for this issue: •
Cheating and making prefabricated panels as walls and losing part of the information because Revit walls are continuous and are not limited in length, which is not the case for real panels.
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Producing windows that are face-based instead of wall-based. It will take time and the result would be very difficult to implement because of the specific relations that a window and a wall share.
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Replacing the whole prefabricated panels system by “Curtain walls” systems. Thus, the wall is replaced by panels and the window hosted on the curtain system is another kind of panel. Changing the kind of panel will automatically update the model, allowing the designer to easily know the amount of each panel needed. In addition to that, it is possible to produce curtain wall-based doors and windows. This solution has the advantage of keeping data about the prefabricated panels while still being easy and rapidly adaptable as a classical wall is. 32 | P a g e
Tool For Augmented Parametric Building Information Modelling For Transformable Buildings | Francois DENIS As a conclusion, the hosting system is very developed in Revit. While combining Parametric Design with the BIM process embedded into Revit, those hosting system would be essential. Actually, the hosting system is working as a list of boundary conditions for the elements. It avoids doors to be placed on slab or walls to be built horizontally. Thus, having a Parametric Design interface that is allowed to define and play with this hosting system will definitely help to improve the global workflow of BIM and PD and bring an added value. b
Level Of detail
The architectural representation is defined through different scales: a plan drawn at a scale of 1/50, 1/100 or 1/500 should not be represented using the same line's thickness or the same precision. In Revit, an element can be defined through three different level of details: Fine, Medium and Coarse. This feature is very interesting but, in order to be fully useful, it has to be well used. The first guideline is to clearly select the information we want to model in 3D. Some elements, such as the drawers in a table, are not needed on the 3D interface. However, they could be useful in a section view of the object. If one family of the project is too precise, it is not problematic but, if all the 1000 families of a project are too detailed, it will cause freezes or crashes. The second guideline about the level of detail is simply to avoid duplicated geometry into the different levels of detail. The line representing the edge into the Fine representation should be the same in the two others. It will reduce the amount of information into the family and thus, increase its efficiency and reduce its size. Thus, the three levels of details should be produced from the Fine to the Coarse. The first drawing is the more detailed and then, part of the lines are “removed” for the two other levels. Finally, the last advice is a rule of thumb used in order to filter the different lines into this hierarchy of representation (Table 2): Table 2: guidelines about the level of detail according to the dimensions of the elements (BIMstore, 2012)
Dimensions
Level of Detail < 25 mm 25mm
