Simulation Of Smoke And Cloud For Taihu Lake Basin

Smoke and cloud simulation is a hotspot in Computer Graphics. It is widely used in computer games, film and TV special effects, scientific computing visualization and military simulating. For the motion of smoke and cloud in the physically-based simulation strictly conform to the physical law, the effect of simulation by this method is vivid. In virtual Taihu lake system developed for some Supervising Department in Suzhou, the main task is to simulate the smoke and cloud in the lake on PC.We use Navier-Stokes Equation in fluid dynamics as the mathematic model of smoke and cloud. For the exact solution of the equation hasn't been worked out, we adopt numerical method to solve it. First we adopt solve by part strategy and map the solving process to GPU (Graphic Processing Unit), so we can solve the NSE quickly. At the same time, we apply MacCormack format to solve the advection item of NSE, which make the velocity and density more accurately.We adopt improved Ray-Casting to render smoke and cloud and map the entire arithmetic process to GPU. For the smoke rendering, we take the approach of ray-tracing twice and achieve satisfactory results. For the cloud rendering, we simplify the model through level of detail technique and add indirect illumination to the rendering of cloud to make the rendering vivid.We add refraction to scene rendering and adopt the approach of perturbing the texture coordinate to carry out refraction on the lake. We get over deformation of refraction through masked identifier. Finally we use scene synthesis technique to realize the real-time simulation and rendering of smoke and cloud and satisfy the task.