Multimedia Methods For Presentation Based On Cad ... - IEEE Xplore

Multimedia Methods for Presentation based on CAD data in Industrial Product Development

Prof. Dr.-Ing. Paul Drews

Dip1.-Ing. Michael Weyrich

European Centre for Mechtronics, Reutershagweg 4, 52074 Aachen, Germany

European Centre for Mechtronics, Reutershagweg4, 52074 Aachen, Germany

Abstract: Thispaper describes multimedia approaches for the presentation of industrial products based on CAD data. Product presentation in an early project state is a key factor to ensure that a design and construction is well matched with the requirements and favoured by the customers. The methods of Computer Animation and Multimedia Interactive presentation are presented. An example of an industrial construction machine design is used to outline the procedures, problems and potentials of the approaches. The research results were intensively studied by means of demonstrations to industry and public regarding their ef$ciency and the scope of industrial applicability.

11. SCOPE OF PRODUCT PRESENTATION People involved in product presentations come from very different backgrounds and emphasise on diverse aspects of the product under development [7]. Product Marketing for instance usually demands high quality photo-realistic presentation. The customer has an interest in the overall concept of the product, certain functional aspect and may also appreciate a high quality visualisation. On the other hand, a design engineer is hardly interested in the photo-realistic presentation of the product but pays probably emphasis on the functional aspects.

I. INTRODUCTION In the development of products today, there is a high demand to present the product at an early design stage [I, 21. By means of photo-realistic and interactive visualisation methods one will have an impression of the final system or product prior to actual production. Thus, market potentials and all types of design aspects may be evaluated in the multimedia presentation to ensure that the real requirements are conceived at an early stage. The presentation of planned products has a significant impact on the development whereby, experts from all areas of the product’s life-cycle may be involved [5, 81. The groups relevant in the product development are highlighted in Fig. 1.

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! Fig. 2: Product Presentationand Evaluation

Fig 2 shows the aspects of a presentation, which may gravitate between a pure photo-realistic presentation and a virtual simulation of functional aspects [5, 61. Different solutions emphasising the aspects of visualisation, interaction and simulation are situated inbetween the two extremes.

User Designer / En~neer Production Manager Production Engineer (also tool designer) Salesman Fig. 1: Groups relevant in product development

Manager

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Requirements manufacturingsimulation, quality, hctionalitv of -Product. ... economic results, figures quality simulation, off-line programming, optimisationprocess (arc welding, robots)

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technical visualisation (presentation), interaction visualisation, presentation

Table 1 gives an outline of the different requirements. The usage of the presented computer animation and multimedia technology is mainly seen in the sales, general management in collaboration with design / engineering. 111. PRESENTATION METHODS To give an impression of the potentials of multimedia presentation approaches various concepts are highlighted in the following. The overview concentrates on computer animation, interactive multimedia presentation and Virtual Reality (see Fig. 3).

In the modelling process, a 3D-model is imported from CAD, structurally optimised and textured. Then in the animation phase action is put into the scene. Lastly, during rendering and video production all images are calculated using computer ray-tracing techniques and are recorded on tape.

i Modeller

3D-Model

Fig. 4b: photo realistic image of the road paver

The interactive Multimedia presentation can employ high-quality ray-traced animation sequences and runs on a cost efficient platform. This makes the system advantages for industrial presentations. However, the approach is limited to a set of pre-compiled and carefully mastered sequences.

Rendering

Fig. 3: Overview of the available Presentation Methods

A. Computer Animation Computer animation refers to the artificial production of photo realistic images. Computer animation systems come from the area of movie productions and are extensively used in entertainment and advertising. The image quality is extremely high and may include complex effects such as shadows, smoke etc. Computer animation systems and their hardware platforms need less resources, which makes them interesting for industrial visualisationpurposes. The a CAD Model before and after high quality realistic rendering is shown Fig. 4. B. Multimedia Presentation CD-ROM data storage capability and a Multimedia authoring system such as Multimedia Toolbook allow the creation of interactive applications. The approach used here records computer animation sequences of all relevant events on soft-video. A carefully formed control scheme reacts to the interaction of the user and activates the appropriatevideo sequences (see Fig. 5).

Fig. 5a: Screenshot of the Multimedia Presentation Environment IM

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walk through passing: p o : pr : p 2 : P3: p4 : p s activates Videosequences: '0,+',2~'23~

Fig. 4a: Model of a Road Paver. left: Rendered with Textures and material; right: CAD-Volume Model

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Fig. 5b: Control scheme of the multimedia presentation

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from the above, there are technical criterion where upon the methods can be compared (see Fig. 6).

C. Virtual Simulation Virtual reality environments are real-time interactive visualisation systems dedicated to exploitation and evaluation. Fast navigation in large scale environments and animation of virtual objects is emphasised. Interactive simulation provides support for fast exploitation of logistical processes, factory layouts and large scale products such as construction machines. Modules for robotics, logistical simulation and prototyping with virtual assemblies have been developed and studied in pilot applications [3]. The projection set-up used in our experiments is the Description Wall which is a 4mx3m large off-screen projection based on CRT-pro-jection technology. The setting is equipped with several IR transmitters to ensure an uniform distribution of the trigger signal for Crystal Eye Shutter glasses.

V. CONCLUSION The overall objective using computer based design tools in industries can be reduced to a few basic headings: decrease costs, shorten cycle time, improve product quality and reach customer satisfaction. Multimedia presentation was intensively studied and could demonstrate the significance to provide for a better communication between the groups relevant in the product life cycle. As mentioned, different people have different requirements for a product presentation which can not be fulfilled by one method at a time. Computer animation technology is time consuming in preparation but provides excellent photo-realistic images. CD-ROM based Multimedia presentation entails additional work, nonthdess it is valuable for the presentation of industrial products in marketing. Virtual Reality technologies is powerful for exploitation and evaluation of data in real-time, however expensive computer systems are necessary. In the near future, decreasing hardware costs will enable the use of a new generation of presentation tools in industrial product development. Those are to be part of the CAx chain, whereby an extra step after the CAD will be included to evaluate a virtual prototype under deliberation.

IV. COMPARISON OF THE METHODS All three approaches have their particular advantages and disadvantages. Cost and the scope of applications are the main factors for an assessment regarding the use in industry. Computer Animation systems are available for PCs which makes production even with low cost equipment, generally possible. However, the procedure of video production is off-line and very time consuming. Rendering of complex data for video production may require days. Additionally, Multimedia Authoring tools may be used for the sake of CD-ROM based interactive presentation of video or virtual reality sequences. Authoring tools provide comprehensive ways of presenting preprocessed video sequences interactively. Virtual Reality technology may alternatively be employed. Today’s advanced graphic computer systems allow the production of realistic presentations and interactive evaluation in real time. However, despite powerful computer systems available today, the level of detail in a scene is fairly limited.

VI. REFERENCES Boulanger, P.(ed.): Rapid product development technologies. Boston, Massachusetts, 1996 Brunet, P. (ed.): CAD tools for products, Kongr.: Dagstuhl Seminar ; (Wadern-Dagstuhl), 1995 Drews, P.; Weyrich, M.: A system for Digital Mock-up’s and Virtual Prototype Design in Industry: ‘The Virtual Workbench ’. Proceedings of the IEEE International Symposium (ISIE ‘97), Vol. 3, pp. 1292-1296, Guimaraes, Portugal, 1997 Drews, P.; Weyrich, M.: The Use of Virtual (in German) Prototypes in Industries. Konstruktions Praxis, Nr. 12, Vogel-Verlag, Seite 22-23, December 1996 Drews, P.; Weyrich, M.: Virtual Manufacturing An Overview. VR-News, Vol. 6 Issue 3, pp. 18 22, April 1997 Menon, J.; Horn, W.: Virtual prototyping of product structure in product data management. IBM - RC 20378, 1996 Rix, J. (ed.): Virtual prototyping: virtual environments and the product design process. Proceedings of the IFIP WG 5.10, Chapman & Hall, 1994

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Wilson, J. R.: Virtual reality for industrial application : opportunities and limitations. Univ. Press, Nottingham, 1996

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Fig. 6: Comparison of presentation approachesApart 0-7803-4503-7198/$10.00 1998 IEEE

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