| As a core technology in Computer Aided Design System, real-time rendering fulfills designer's needs for photorealistic pictures and real-time interaction with the scene. Virtual Reality is a new trend of the CAD new technology. This article firstly analyzed the application of computer graphics and virtual reality in three dimensional CAD. Then designed a mechanical product design virtual studio, realized real-time rendering by using graphics hardware. The system provides designer with functions such as interactive product manipulation such as geometry and surface properties, walk-through assemble scenes and stereo viewing. It can help designers to communicate with users more effectively and optimize design quality.Works are as follows:1. Designed the hierarchy of Virtual Studio. This hierarchy is component-based and consists of data library, functional components and interface management components. It is an extensible structure.2. Constructed a new file structure which holds both the scene and model data. Model structure is reorganized to meet the need for selection policy3. Integrated four different windows to provide users different interaction patterns. It can be used to observe and manipulate the scene.4. Introduced a new conception - reorganization of geometry transformation. Interactive manipulators are designed to deal with subsets of transformation.5. Designed and implemented three dimensional real-time rendering components of the system. It includes scene lighting, shadow mapping, fog, material and textures. |
