Smoke Simulation And Implementation Based On Vortex Particle Method

A variety of smoke phenomena can be seen everywhere in real world; hence smoke simulation techniques which produce realistic and efficient effects have a broad application prospect. This paper choose the vorticity equation in fluid dynamics as the intrinsic physical basis of our smoke model, study on the topic of smoke simulation using a method based on vortex particles, and analyze the feasibility and applicability of this method, then carry a further research on the implementation details.This paper studies the smoke simulation methods at home and abroad. After analyzing the merits and drawbacks of the two most popular fluid analysis methods, i.e., the Lagrange method and Euler method, we apply a hybrid scheme to our method. This method compute the velocity field using discrete grid in Euler framework first, then trace the motion of vortex particles in Lagrange framework. We use a hierarchical uniform grids structure to discrete data, and solve every item in vorticity equation based on it. During the solving process, we need to use velocity, so Biot-Savart Law is used to compute velocity from vorticity. Since the solving process needs to consider the interaction between every vortex particle and all the other particles in the system, the computational overhead would be a heavy burden when the simulation process contains a large number of particles. To simplify this problem, this paper use particle clustering method, the multiple particle effects are superimposed as a super particle, in order to reduce the amount of calculation. Experimental results show that this method does not substantially affect the visual effects, while at the same time enhance the computing speed, reaching a real-time result for smoke simulation.This paper also analyze the interaction problem between smoke and other rigid bodies and proposes a method to satisfies the no-through and no-slip boundary condition by placing a vortex particle on the contact surface where the vortex particle collide with the body. The experiments display several scenarios in which the smoke interact with other bodies and the experimental results show that the method can handle the boundary conditions well and achieve a good control effect.