stooch

Hi, disable the velocity masking field in the pyro solver options, the velocities are being multiplied by the density field, which means that immediatelly outside of the density, velocity is set to 0. to avoid this, either make a custom field or disable density masking entirely.

sometimes people run into weird motion blur issues because they alter the point count (say by deleting via frustrum) - this could break motion blur or introduce artifacts. if you are altering point counts, you need to be using a trail sop to generate velocities BEFORE any delete/fuse operations to get stable results. easy to forget this in the heat of the moment

by modifying the vector "spritescale" (x,y) with a vop sop.

no answers for this? i see this bounding box even on a cached sim, is there no way to just delete some group or something? i really dont want to see it for precomp

what you are seeing is normal houdini behavior. The particles are squeezing into one grid voxel and are being advected around as a bunch. This is what particle separation does for voxel based solving, it ensures that particles don't get squeezed into one voxel. If you are introducing outside force, i think you need to use particle separation imo. The reseeding causing your to lose particle cound is a hint that your particles are being squeezed so the solution is to enable separation or use normal particle fluid solving.

the solution to this is a variable viscousity solver that is based on heat. so as you add heat, viscousity decreases, but heat discreases over time and viscousity increases. with a heat value taht is over some threshold you can actually make the particle freeze in place using object space.