Particles sometimes ignore collision

[anonymous_user_7d67aec5]

Hey guys, I’m still kinda new to Unreal Engine.

I followed a YouTube tutorial a while ago, it was explaining how to make snow-looking particles.
The guy demonstrated how to make particles disappear, but some particles still manage to get through solid objects. It became obvious today when I made a simple building for testing purposes (walls were made with Shell modifier in Max).

Here’s a screenshot from Cascade

Changed response to “Stop” so I could show you that instead of stopping on the roof, they fall through.

As shown, some particles go through walls and roof without stopping. The case seems to be worse if you constantly rotate the camera. So for example, when you jump inside the building, there’s a bunch of snow, but the amount of snow particles decreases as you stand still and don’t move the camera around (snow doesn’t completely disappear). If you turn the camera 90 degrees or more and look at the other side, you’ll see the same thing - snow was falling through like mad, but gradually decreases.

I know I did something wrong, but I can’t figure it out…

Help, please!

[Nachtmahr]

Thats normal behaviour you See there on GPU Sprites. The Collision uses Scene Depth and not “real” Collision. And Scene Depth is Rendered by the Camera. So everything outside your Camera has no Collision at all thats why your particles Fall trough when you dont look at them.

You can use CPU Particles Collision they dont need Scene Depth but will Cost you more.

[anonymous_user_7d67aec5]

Thanks, but how do I switch them to CPU particles?

[Nachtmahr]

Its a CPU Particle by default just remove the GPU Sprites Module. You can also set it to Mesh Data explicitly if you like. Make sure you add a Actor Collision Module and make your “Bounds” somewhat big (I recommand fixed Bounds). If the Camera cant See those Bounds it will Skip Collision Checks. Adjust Modules to your needs.