I am wanting to make snow accmulate in Unity I have tried the World Collider for partical effects but it just causes it to bounce off the terrain and disapear. Any one know a way to make it stack up?
check out rainscape it does it for filling up cups of water. would probably be a similar prossess for snow, though somewhat less flat
Having true snow flakes (small physical objects) stack is a horrible idea for a game. One, the number of objects will get really high really quickly. Two, the physics calculations will get very resource intensive (also really quickly).
What you need to do is to fake it. I would advise using a mesh to simulate the top of the snow and slowly increase the height of the mesh over time as the snow falls. It wont be perfect, but it should achieve the desired effect.