I think it would be possible to do Imposters with Unity as it is… I’d love to figure out how.
As far as SteepParallax… well, that can wait a few years to when GLSL finally truly comes to Mac and graphics cards as powerful as the 6800 are low end… making it worthwhile for someone to write a GLSL shader for this using the new Unity Shader Engine 3.0 :shock:
Just remove the particle animator from the particle system and enable one shot in the emitter.
You might want to use the particle mesh emitter, which emits from the surface of a triangle mesh, so you have more control over where your particles are spawned.