Hey there I used the P_SnowFlare Particle system from the Particle Cave demo to create snow in my Level. But how can I make that the snow doesnt fly through wall and I doesnt see the snow particles in buildings ?
Take a look at the collision module from cascade: https://docs.unrealengine/latest/INT/Engine/Rendering/ParticleSystems/Reference/Modules/Collision/index.html 
But they are GPU sprites andthere I only have Collision (Scene Depth) and if I play around with the settings a bit some of the Particles gets blocked my Walls but some fly through so not every particle gets blocked. Is there any fix for that ?
The only fix for that is not to use gpu particles I’m afraid.