Particles affected by light ??

Is there a way to make the particles interact with light as if they were a mesh? ,

for example, the bottom particles of the emitter would be dark and the top would be bright?

Thanks.

I Found its good to make a gradient over the particle texture and it looks a little like your going for...

It would be quite hard to render something like that in realtime.

You could also try the particles/vertexLit shader.