Particle collision

[Spazatron]

I have a rain particle to make it look as though it's raining outside a window, but the rain is going through the ceiling of another room in the building. I can't simply move the particle because it's positioned perfectly at the window... is there a way to stop the particle going through the ceiling (which is a primitive)?

[Mudbill]

No I don't think you can add collisions to them.
The rain particle is really huge in radius, so if you want to, you can edit it to be smaller for yourself.

[FlawlessHappiness]

No, you cannot.

So there are 2 solutions:

Move it up, so that it doesn't collide with what's below it.
or
As Mudbill said, create one yourself.