trs79

17-11-2011 21:35:03

Hi,

I'm trying to create a simulation where SPH particles are filling a small jar with roughly the same circumference as a glass mason jar (about 10cm). I'm currently using PhysX 3.1 as the simulation, but as the particles fill the jar they jitter uncontrollably. My understanding from research is that SPH is calculated at real world scales, or roughly a grid cell size of 1cm^3. My mason jar is about 10 cm^3, and my game world units are in meters, so I figured I should get the particle positions back at simulation scale without scaling them up.

The problem is I can't seem to get a stable simulation until I pass much larger values into PhysX, i.e. it has 0.02 as a rest distance default unit (docs define as "the typical particle distance of particles in the rest state (relaxed). Defines the particle resolution of the fluid. "), but until I go all the way up to 0.8 I can't get the particles to be stable. And by the time the rest distance is that large the particles seem to move very slowly, i.e slower then real-time (I assume because of the larger scale) plus the mason jar is many meters in circumference!

I appreciate any clarification, thanks!

I'm trying to create a simulation where SPH particles are filling a small jar with roughly the same circumference as a glass mason jar (about 10cm). I'm currently using PhysX 3.1 as the simulation, but as the particles fill the jar they jitter uncontrollably. My understanding from research is that SPH is calculated at real world scales, or roughly a grid cell size of 1cm^3. My mason jar is about 10 cm^3, and my game world units are in meters, so I figured I should get the particle positions back at simulation scale without scaling them up.

The problem is I can't seem to get a stable simulation until I pass much larger values into PhysX, i.e. it has 0.02 as a rest distance default unit (docs define as "the typical particle distance of particles in the rest state (relaxed). Defines the particle resolution of the fluid. "), but until I go all the way up to 0.8 I can't get the particles to be stable. And by the time the rest distance is that large the particles seem to move very slowly, i.e slower then real-time (I assume because of the larger scale) plus the mason jar is many meters in circumference!

I appreciate any clarification, thanks!