Katherine Blizard


Smoothed Particle Hydrodynamics

In Winter and Spring 2011, I will be working on a implementation of Smoothed Particle hydrodynamics. The non-lighted version runs at interactive framerates. These particles behave like a gas or fluid in space, in this case they are kept in a large box. TO show clarity, the particles are colored based on their position in space, with some variation to clearly show the different particles. The box here pictured is 10 meters x 10 meters x 10 meters.

Currently progress is at the point where the underlying voxel structure is being integrated with the program to the optimize speed a little. These two videos are from the last stable version of the simulation, when there was a dummy data structure in place of voxels. These two videos below demonstrate the simulation with two different viscosity levels. Since I did not finish optimizing the program and some CPU power will be taken by video capture, I set the number of particles at 300. Also, I placed music on the videos to get rid of the terrible noise the video capture program put in them.

These particles are modeled after Desbrun and Gascuels Langrangrian implementation of Smoothed hydrodynamics. Each particle has a mass, density, location, acceleration, smoothing length and velocity. The Physics engine models gravity, pressure forces, and viscosity. They are encased in a 10 meter cube that cuts off their acceleration and velocity. Collision itself was producing ugly artifacts, and this is the latest problem of the project I am working on. Getting the box to appear right will allow me to put the voxel structure in, and this will allow me to optmize the neighbor search functions. Those functions are the main bottleneck to the program's real time performance. After the voxel structure was put it, I was going to represent the voxels as texels in the GPU. This should optimize the simulation further.

References:

M. Desbrun, M. Gascuel "Smoothed Particles: A new Paradigm for animating highly deformable bodies."

T. Harada, S. Koshizuka, Y. Kawaguchi "Smoothed Particle Hydrodynamics on GPUs"

Harris, M., Baxter, W., Scheuermann, T., Lastra, A.: Simulation of cloud dynamics on graphics hardware.

C. Braley, A. Sandu "Fluid Simulation For Computer Graphics: A Tutorial in Grid Based and Particle Based Methods"