Most of the VR environments require the completion of a building model before it is imported and displayed in the VR space. In other words, design can’t be executed transparently and directly in the VR space, and its product can’t be visualized intermediately. As such, the technology sets up limits to the flexibility and plasticity of its application in the design processes, which is a drawback. For example, a full-scale model can show every building part. Designers can discover that a beam is not in the right position, and the entire section of a building needs to be redesigned and the model rebuilt.
After the remodeling is done, a new model is needed. In the current VR setting, one can not go backwards and compare the new with the old version just by reloading a database. Therefore, an on-line computer system and methods of saving design data are needed. Meanwhile, a designer has difficulty designing in VR without having any tools available.
If there are building materials and modelling operators available in virtual space, designers can simply select and execute rather than constructing the building model outside the VR space. This is the notion of building a CAD system to help with design (Sutherland 1965, Foley et al. 1990). An ideal CAD in VR should have selection icons as inventories stored in VR for 3-D modelling. Similar efforts can be found in 3DM (Butter-work et al. 1992) and ISSAC (Mine, 1995a). To enhance design in VR to make it more productive and user friendly, it is necessary to install a CAD in the VR space. This is one of the ongoing projects of Architectural Design Virtual Environment (ADVENT) at ISU. The goal of ADVENT is to set up a design environment in which design activities are executed, metaphorically speaking, by manipulating and constructing three-dimensional building blocks. The 3-D building blocks are any 3-D building materials stored in the VR space. Users can apply any 3-D elements or customize their own building elements (e.g. structural parts, special columns, beams, bricks, etc.). In this system, design thinking occurs while operating the 3-D elements to construct the concepts of the designer.
Development of VR in Design
Until now, architects have had to communicate their design ideas through scale models and perspective drawings. If clients wanted changes, drawings and models needed to be redone. A tool that allows the clients to visit the design and to walk around in it before it is built, would benefit architects and clients tremendously. Frederick Brooks at UNC had modeled the new computer science building, Sitterson Hall, with working drawings as a guide.
Using a powerful graphic computer, the viewpoint can be positioned anywhere in the model for rendering. By controlling speed and direction, consecutive interior and exterior images can be generated. With the use of a treadmill and handlebars, users can physically walk down hallways.
Other programs for architectural walkthrough were also developed at UNC to generate a visual tool for evaluating design concepts (Brooks, 1986). The first commercial VR product for marketing design concepts is the virtual
kitchen designed in April 1991 by Japan’s Matsushita Electric Works. Customers can experience what a custom-built kitchen will look like (Bylinsky, 1991).
These computer simulations provide designers and clients valuable knowledge that can be used to improve the environment and design. John Walker, one of the founders of Autodesk, started the “Autodesk Cyberspace Initiative” in 1988. Applying the VR peripherals of glove and goggles (head mounted display), they started VR in PC platforms. The first product is the core of a new object-oriented 3-D simulation language entitled “Cyberspace Development Toolkit.”
This toolkit provides programmers with an easy way to create complex virtual environments. Detailed introductions to the VR history and current development can be found in Pimentel and Teixeirz (1995). Other information about VR in design are in Bertol (1997).