My deadline is coming up and I have a few small problems that I quickly need to resolve.
I have a snow covered car.
The snow falls off the car to reveal a new body-paint color. The source is a pre-constructed, scattered and point-replicated point cloud on top of the car geometry, revealed based on input particles from falling snow. (I used attribute transfer with a solver node for that) Everything is working fine, except of course that all my particles are dropping from the car, simultaneously. My question is; how do I start them off "frozen" and have them fall based on my input? I was imagining an animated noise pattern so control the activation, of sorts. But maybe an animated metaball setup? I am just not sure what particle attribute to use. The "active" one doesnt seem to do anything.
Ideally I would like this snow to be grains, so that I can have clumping and stacking, but since I am colliding with car geometry, the grains always explode. Is there a way to maintain constraints without everything exploding? I am using a vdb collision volume sample of the car. It looks like Houdini automatically adjusts the particles so that there are no intersections with the collision VDB, but I cant seem to get away from the explosion.
How the hell do I get geometries with a shadow matte shader assigned, to not cast shadows on one another?! but only from objects that are NOT a shadow matte?
I am basically just trying to render this snow out in two passes, and one is a shadow pass. I only want shadow from the snow, affecting my ground and the car. But no shadows from the car affecting the ground & vice versa. Much like Vray's material wrapper.
I have 6 licenses but have not yet set up HQ server. Could anyone briefly explain the process of getting this setup?
Thanks so much for any help and input!