| Generating a visually convincing image especially for those dynamic fuzzy objects is one of the most challenging and difficult problems in computer graphics. And the effect produced by these dynamic fuzzy objects is one of the most important components of the Virtual Reality.On the basis of consulting relevant documents, some theory and algorithms of modeling and simulating dynamic fuzzy objects, such as particle system-based model, fractal-based model, texture-based model, are researched in this paper. A new derivative state is attached to the original particle system to simplify the difficult to simulate the complex dynamic fuzzy objects, and to achieve some special effect. By using of different textures in the different time, or by changing of the object's contour that will be filled in texture, the animation can be produced in the 3-D space. And the dynamic fire is simulated successfully by these two methods. In consideration of the system's efficiency, a distance flag can be placed to switch the different fire. When the distance between the object and the eyes is less than the flag, the particle system-based fire will be rendered. Otherwise, the texture-based fire will be rendered. In the generation of the Virtual Environment, some problems are discussed, such as the relation between the number of active particles and the rendering effect, the reasonability of the speed to change the texture. At last, this paper puts forward a method to appraise the scene of the Virtual Reality based on visual angle relation. |
