Research On Dynamic Water Scene Modeling Method For Tai Lake Water Area

Virtual Reality is a new and integrative information technology, which integrates many information technologies and gives people a strong support in building and expericing virtual world. Virtual Reality has been used in many fields. In virtual scene, especially in outdoor virtual scene such as flight simulation,game,virtual city and war game system, dynamic water scene is a very important part. In virtual Tai-lake system developed for some Supervising Department in Suzhou, the main point is to simulate the real dynamic water surface effect including lake surface's waves and reflectional,refractional effect.Based on the requirement which has been described, Tai Lake water area has been divided into two parts: large and small water area after taking a deep research of dynamic water surface's literature nowadays. In addition, different modeling and rendering algorithms have been taken advantage of to simulate the dynamic water surface. To the large water area, improved Perlin noise is introduced as the stimulator of the water height field.With the smoothness characteristic of the noise, continuous dynamic lake surface effect is obtained. At the meantime, with the help of Johanson's projected grid algorithm, the lake surface grid mesh has been modeled. Moreover the great graphic processing ability with vertex shader and pixel shader has been taken advantage of to realize the vertices'processing method based on the GPU and simulate the lake's waves in reality. To the small water area, the water surface's fluctuation has been focused on when the rain droplets drop into the water this article. 2-D wave equation is introduced to describe the fluctuation.Explicit finite difference scheme and programmable GPU technology is used to solve the equation and get better result in the reality and real-time requirement.In the dynamic water surface's rendering algorithm, The 1-D texture is used to reflect the Fresnel Term. The refraction and reflection is adjusted to simulate the refractional and reflectional effect with the fresnel term. In the meantime, the alpha channel in the local reflection has been taken advantage of to adjust the global and sunshine's reflection in order to simulate the lake which has dynamic sunshine on it. From the experiment, the simulation about the dynamic water surface in the algorithms'model this thesis is real-time and near to real scene on the commodity PC.