|
Fluid simulation areas, particularly simulation of natural phenomena, such as thechurning smoke, turbulent streams and floating white clouds, because of their complexand ever-changing appearance, has always been a hotspot and difficult topic in computergraphics research. Smoke simulation has a wide range of applications in the militarysimulation and training, interactive games, movie special effects, fire simulation,advertising and so on. But with the constant increased demand for computer vision, moreand more graphics researchers are focusing on the specifics of the smoke and theimprovement of the frame rate. This paper is based on physical methods to study thesmoke simulation, thereby increasing the authenticity and real-time performance of thesmoke simulation.Firstly, introducing multi-grid v cycle optimization algorithm for solving the pressureitem in physics model, N-S(Navier-Stokes) equation, can improve the real-time smokesimulation. Organizing grids with various degrees of subtlety in our algorithm can producea swing component based on relaxed smooth characteristics of the fine grid andattenuation of interactive process. Then using limit operators and interpolation operator toremove the error component of iterative processes, can accelerate the iterativeconvergence rates, and increase the speed of calculation, therefore it ensures real-time ofthe smoke simulation.Secondly, by proposing to add the limitation of the space adaptive whirlpool, asexternal forces item, into the process of the N-S equation, smoke details of small scale canbe maintained, and the smoke performs more naturally. The whole grid with variablespace spiral swirl on strengh will be displaced with the coefficient constant. And, inlow-resolution grid, limits of adaptive whirlpool works as an external force for solving theN-S equation. Then, by sampling speed, b-spline interpolation reduces the amount of highresolution to solve calculation. Finally in high resolution, mixing the limits of the adaptivewhirlpool with velocity field sample can remove the noise in the process smoothly, andcreate a whirlpool detail of authenticity. Finally, the results of improved algorithm with C++and OpenGL on the computershow that the algorithm discussed in this paper, not only can ensure the real-time of thealgorithm, but also generate a more nature smoke simulation.
|