Direct Manipulation Interface for Architectural Design Tools Dzmitry Aliakseyeu User-Centered Engineering group Faculty of Technology Management Eindhoven University of Technology, The Netherlands Email:
[email protected] ABSTRACT The early architectural design stage is a typical example where traditional design tools such as sketching on paper still dominate over computer-assisted tools. Augmented reality is presented as a promising approach towards developing interaction techniques that preserve the naturalness of the traditional way of designing, while at the same time providing access to new media. Based on the analysis of user requirements and requirements for a natural user interface, a working prototype of a new interaction platform for architectural design was created.
•
Keywords Augmented reality, Architectural design, Natural User Interface
Secondly, it is important that the tool can handle more representations at the same time, meaning sketches, images, text and 3D models. A sketch is a very powerful representation, it is vague on purpose: sketches can therefore often be interpreted in many ways. An image can inspire the architect: sometimes it displays materials or atmosphere that the architect likes, or it displays a certain composition of proportions, which appeal to him in an esthetical way. Text is used as annotation, explanation or as keywords; sometimes it is used in schemes or in a description of the conceptual ideas.
MOTIVATION In current architectural practice, preliminary designs are mostly created on paper and/or in a scale model before being converted into a representation in a CAD (Computer Aided Design) program. Only a few computer tools are available to assist designers in this early (or conceptual) design stage. The problem of introducing computer technologies at this stage is that the designer needs freedom, speed, ambiguity, vagueness, etc. to quickly create the (usually only partially specified) objects that he/she has in mind. This absence of strictly predefined rules, which is inherent to the traditional design media, is not offered by currently available computer tools. RESEARCH PROBLEM The aim of the project is to design and evaluate a direct manipulation interface for architectural design tools. The main research question of the project is: Is it possible to substantially improve the early architectural design stage by adding supporting computer tools? This question can be divided into two subquestions: • What are the characteristics and the requirements of the early architectural design stage?
How to define and measure the effectiveness and satisfaction of proposed computer tools for the early architectural design stage?
When thinking of requirements for computer aided architectural design tools, we must consider the following. Firstly, the architect must be able to sketch, write, model or search for images, or other information, in an easy, intuitive way. Intuitiveness in using the program is important in order to enable the architect to focus on the design problem and not on how to use the program. Intuitiveness can be provided to the architect by a tool that is natural to him.
Thirdly, the tool should be able to handle all information, which is useful to the architect. This can be information concerning the assignment, the situation of the building envisioned, her/his vision on architecture, etc [4]. Fourthly, it is important to consider that besides potential added value of computerization, computers also introduce limitations in the design process. example, Lawson [2] showed that CAD systems are neutral and that they actually encourage poor design.
the can For not
Finally, because of the absence of predefined rules and the vagueness of the early design stage, it is difficult to derive a priori how computer support tools should behave in detail. Therefore we have implemented a prototype of a system for architectural design which attempts to meet the user and system requirements mentioned above. IMPLEMENTATION
Copyright is held by the author/owner(s). CHI 2002, April 20-25, 2002, Minneapolis, Minnesota, USA. ACM 1-58113-454-1/02/0004.
Interaction Elements The system has three basic interaction elements, namely, the brick elements (BEL), a digitizer tablet with a digital pen and the enhanced paper prop (EPP)[1].
The brick elements are physical objects coated with infrared reflecting material that can be tracked by the system using the camera. The BELs are used for selecting and positioning the virtual objects on the working space. The Enhanced Paper Prop (EPP) is a real piece of paper, that can be placed on the horizontal workspace. The EPP contains infrared reflecting tags that allow the system to track it. Sketches made on the EPP, using the digital pen, can be traced into the computer. Sketches can either be projected onto the paper or can be created by digital pen with an ink cartridge. The Wacom UltraPad consists of a tablet and a digital pen. The digital pen can be used like a conventional mouse or as a writing tool. In our current implementation the digital pen is used to make menu selections, sketches and annotations. Interaction Technique
digital copy of the EPP, which can be used later as virtual paper. EVALUATION We plan two steps in a system evaluation. As a first step we plan usability testing in order to identify usability problems in the interface. This evaluation will be performed in the form of a walkthrough guided by a scenario. The goal is to motivate the user to use all functionality in the interface (e.g. task with overdrawing) As a second step we plan a comparison test between the current practice and our proposed system. One or more architectural assignments will be given to two groups of participants (student architects). One group will perform the assignment using the system and a control group will use current technology. Afterwards the results will be given to domain experts in order to judge the results. In order to clarify the specific actions performed during the test session and the user satisfaction, participants will be asked to fill out a questionnaire after completing the assignment. CONCLUSION AND FUTURE WORK The prototype system can help in managing, storing and annotating images; managing, creating and editing sketches and can assist in re-drawing and over-drawing. This interaction style also preserves the naturalness of the traditional way of sketching.
Figure 1. Architectural Design tool layout. 1Image database browser, 2- Floating toolbar, 3-Virtual Papers, 4 – Enhanced Paper Prop. The layout of the system (see figure 1) consists of an image database browser (1), virtual paper (3), a floating toolbar (2) and the EPP (4). The virtual paper (projected image) contains: previously made or scanned sketches; inspirational photos for example, work of other architects; images from previous projects; and/or other relevant material. These materials can be retrieved from the image database browser. By moving the BEL with the non-dominant hand, the designer can change the position and orientation of a virtual document. A digital pen in the dominant hand can be used to annotate or sketch on the virtual paper. This annotations or sketches can be saved or printed for future use. The VP has several properties like transparency level, size, sketching ink color and pen thickness. To adjust these properties the user can use the movable semitransparent toolbar. Using the EPP the user can create sketches in the traditional way while the system offers additional functionality [3]. The system can add visual information that supports the design, since any virtual paper can be placed on top of the EPP. The system also allows printing or saving of the
Depending on the results of the experiment and based on available technology and insights into user requirements, our prototype will be improved in compliance with new user requirements. In the next step of the development we also consider the possibility of adding 3D models as part of the system. REFERENCES 1. Aliakseyeu D., Martens, (2001), Physical paper as the user interface for an architectural design tool, in proc. of Interact 2001, July 2001, Tokyo, Japan, pp. 680-681. 2. Lawson, B. (1999), ‘Fake’ and ‘Real’ Creativity using Computer Aided Design: Some Lessons from Herman Hertzberger. In proceedings Creativity&Cognition 99. Loughborough, ACM, pp. 174-180. 3. Mackay, W. & Fayard A.L. (1998), Designing Interactive Paper: Lessons from Three Augmented Reality Projects, Augmented Reality: Proceedings of IWAR’ 98, Natick, Massachusetts, pp. 81 – 90. 4. Segers, N.M., Achten, H.H., Timmermans, H.J.P., Vries, B. de (2001), Towards Computer-Aided Support of Associative Reasoning in the Early Phase of Architectural Design, in Proceedings of CAADRIA’2001, pp. 359-368.
