Improvement In The Real-Time Of Smoke Simulation Based On Navier-Stokes Equation

The smoke simulation has always been one of the most challenging problems in the computer graphics from the 1980s. This project is supported by the National High Technology Research and Development Program of China(No. 2008AAXXXXX) and the National Natural Science Foundation of China(No.60970073). According to the factor which affects the real-time in the smoke simulation, this paper focused on the following areas.Firstly, the number of particles in the particle system which directly affects the real-time and the reality in the smoke simulation is important. The Viewport-driven Number-of-Particles-Created Function was proposed to control the new particle number of every frame. This function reduced the particle number in the smoke simulation, thus it decreased the computer processing time and improved the real-time. In addition, the lifting height of the smoke was used to determine the life of particles. The visual effect is improved great.Secondly, the Navier-Stokes Equation was used to controll the movement of the smoke. The real-time about smoke simulation based on physics was not effective because of the complication in solving the Navier-Stokes equation. The MacCormack method was proposed to solve the advection item of Navier-Stokes. First, the forward advection operator was applied to get the forward smoke volicity. Secondly, the backward advection operator was applied to get the backward smoke volicity. Finally, the computed forward advection data was corrected according to the error estimate. The new method reduces the steps in the Back and Forth Error Compensation and Correction method during solving the advection item which directly affected the real-time and the reality in the smoke simulation. The visual effect is improved and the requirement of the real-time is satisfied according to the optimization.Finally, the real-time rendering of the smoke simulation system was designed and realized to validate the effectiveness of the methods proposed. This smoke simulation system was designed by VC++ and OpenGL(Open Graphics Library). It has been successly applied to the scene of KongTian virtual battlefields.