Hello,
New to Stoke here. I’m having problems with partitioning a realflow sim. I just want to create more seeds from another sim so when i mesh it together with a higher particle count realflow sim it would approximately match the count and meshing in Frost will be good. Here is a screenshot. -TIA
Looking at the right image, I would guess that the voxel grid spacing is too coarse and does not capture the fine details of the source simulation. However, without seeing the actual setup, it is not clear to me how you are seeding the extra particles, so there could be other issues.
Have you considered using a Krakatoa PRT Cloner modifier on top of the PRT Loader to seed more particles around the base particles from Realflow instead of using Stoke? The PRT Cloner modifier has a “Particle Repopulation” option which creates a voxel grid around the existing particles and seeds new particles with similar properties based on the data on the grid. It is roughly equivalent to creating a Frost mesh from the seed particles, and filling the resulting volume with a Krakatoa PRT Volume, except it works without an intermediate mesh.
Here is a Krakatoa for Maya tutorial which uses the same technique, you would simply have to use the Krakatoa PRT Cloner in 3ds Max instead, but the settings are generally the same: https://docs.thinkboxsoftware.com/products/krakatoa/2.9/1_Documentation/manual/kmy/tutorials/kmy_tut_repopulation.html
Since Stoke also generates a voxel grid to capture the velocities of the source particles, and you are probably seeding particles around the base particles of the low-res sim, the results could be comparable, except that the Stoke particles would have a fixed count, while the PRT Cloner particles wouldn’t be consistent between frames.
Thanks for your reply! The PRT Cloner mod works better. I also tried before to load the prt loader inside pflow and create spawns but i think the prt cloner is what i need. i also noticed in stoke that it is making some fluid motions eventhough it was turned off. is this a natural behavior of stoke when partitioned?
When the Fluid Motion is off, we don’t apply any additional operations on the velocity field to remove divergence. However, with large voxel sizes, the influence of the source particle system on the driven particle system can have averaging effects that make it look more “fluidy”. Imagine a voxel with size of 1x1x1 generic units with 100 particles from the Realflow base sim falling in the same voxel. All their velocities will be dumped into the same voxel, and all particles from the driven particle system that fall into the same voxel will get the same velocity. As the size of the voxels goes down, you get a lot less particles into each voxel, and particles in those voxels end up following the source velocities much better. However, if the velocity magnitudes are very large, a driven particle could easily end up being kicked out into an empty voxel with no velocities at all. So particles would stutter, start and stop between frames.
For that reason, I consider the Stoke Particle Simulator a tool for creating new motion from existing motion, and not for following verbatim.
Btw, another way to fake partitioning with a PRT Loader is to just add a Noise modifier on it, change the Random Seed and save multiple times. I even had a Magma setup that could partition such a set up automatically by wiring the Seed of the Noise to a Magma input, but you can probably do it by hand, too. However, the PRT Cloner Repopulation likely produces smoother results.
