Research And Implementation Of 3D Fluid Simulation Techniques

3D fluid simulation techniques have provided amazing visual effects in the field of computer graphics. Therefore, as people become increasingly demanding visual effects, 3D fluid simulation is becoming the focus of attention of researchers. You can see 3D fluid simulation in the movie special effects, 3D animation and video games. 3D fluid simulation is the basis of simulating a variety of natural phenomena at the same time. These factors determine 3D fluid simulation is not only a hot topic at present, but also an important direction for future research in the field of computer graphics.Firstly, we have conducted in-depth research on the theories and techniques of 3D fluid simulation in this thesis. These theories include the physical basis of the fluid simulation, the coupling between fluid and dynamic obstacles and the research of rendering algorithm. Then we have designed and implemented 3D fluid simulation system on GPU. The innovations of this thesis include the improved fluid simulation algorithm, the improved voxelization method and the improved ray-casting algorithm. These innovations have been applied in this thesis. In this thesis, the main contents are as follows:1. The Navier-Stokes equation is the physical basis of the fluid simulation. The fluid simulation algorithm has been deduced according to this equation. Combined with the specific circumstances in the thesis, the fluid simulation algorithm has been improved. The main contents of the improvement include the use of Mac Cormack method to solve the advection, the use of Jacobi iteration method to solve the pressure based on GPU and a method to update level-set by combining advection and correction. We have obtained more accurate results by using improved fluid simulation algorithm.2. We have added the impact of dynamic obstacles to the fluid in the process of the fluid simulation. The coupling between fluid and dynamic obstacles is the key point of this thesis. We have got the boundary and the boundary normal vector of coupling surface by the improved voxelization method. The implementation of the two-way coupling is based on this method. We have achieved remarkable results through the experiment of the coupling.3. The results should be rendered at the end of the simulation. We have used ray-casting algorithm after considering effectiveness and efficiency. Combined with the specific circumstances in the thesis, the ray-casting algorithm has been improved. The main contents of the improvement include the light travel-distance correction, clipping and a method of controlling transparency. We have obtained correct results by using improved ray-casting algorithm.Finally, we have implemented the 3D Fluid simulation system based on GPU and given the experimental results and analysis on the basis of previous research. Then, we have summarized the current results and discussed the future work.