Thursday, 7 November 2013
20131104 maya nParticles fluid simulation water flowing and meshing from Patrick Woo on Vimeo.
A project prompted me to look into Maya's liquid solving and meshing. It is easy to confuse Maya's fluid simulation, particles simulation and liquid simulation.
Fluids solving involves using voxels which cuts up a volume into cells and calculating how density, fuel, and heat moves around in that space, how much and how fast. This takes into account incompressibility, taking into account and preserving the volume of the contents being pushed around.
Maya's solution to representing liquid uses nParticles with a liquid calculation section that also solves for incompressibility. However no voxels are involved. Instead each nParticle has an incompressibility multiplier that pushes its fellow particle away from itself when the neighbour comes within a certain distance from the particle's centre.
The simulation is then configured to have the appearance of a blobby surface. By converting the nParticles to polygon, we can generate a polygonal mesh that has controllable resolution and quality attributes. This makes it possible for the artist to get a good balance between the desired level of detail, and the speed of mesh generation each frame.
In a set-up like this, only the nParticles can be cached. The polygonal mesh cannot be cached, as far as I currently know.
Let me know what you think :)