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Particle Culling?

I’m trying to finish up some rain effects that I want to cut out by distance. I need to make it so that at a set distance said particle isn’t rendered until you get closer. I did something similar to this in UDK3, but can’t seem to find anything on it in UE4. I believe it was called culling in UDK3, and I’m wondering where it is in UE4? Did it get renamed, replaced, or moved?

Hopefully one of you guys can point me in the right direction :slight_smile:

I’m not sure what you mean. Though if you’re saying to attach it to the camera, then no that wouldn’t.

Just looked back on the UDK to make sure I knew what it was called, and it is under “Distance Culling” with options such as near/far cull/fade. So any ideas where those might be now?

I forgot to mention that those above options were normally found in the particle editor. Not sure if that helps anyone, but I hope someone can chime in here.

Ok so here’s a picture of it in UDK3, in case that manages to find some help for me here lol:
9bb243571728f4666a91885b87795fb383ac9ec2.png

I believe your thinking of LOD (level of detail) try looking at that. It’s a feature of the particle system.

Hmm I’ll have to take a look into that. Before I start though will this be a hard snap on/off or a somewhat softer fade in/out like I wanted. I’ve yet to really dig deep/mess around with LODs, my apologies for my noobishness lol. I wanted to use this culling to help with my rain setup that I want to try out.

Around the level I would place my Rain emitter in a grid like fashion, then using the distance culling, it would only render the rain in your immediate area. But as you moved closer to the other emitters they would be raining as well.

TL : DR
I wanted to make it so only the Rain Particle systems in the players general area were rendered so the performance isn’t completely flat lined by having every Rain system going off at once. So does this still sound feasible if I go by LOD to accomplish this?

Sorry for the late reply, There are 2 ways to do this, First way is through the material of your particles like this: Constant Expressions | Unreal Engine Documentation

the second way is I believe if you right click your particle emitter on the content browser and click details you will find a load of stuff that you can set up, One of those is called Occlusion, Experiment with it’s settings and size to get your desired effect.

Best of luck,
Chris.

Hey thanks for the info! Just one question though. When you use the first method, how/where do you set the Cull Distance for it? Or do I have to do a combo of the above? Sorry for my confusion lol.

After messing with the Occlusion settings, I can say that it doesn’t seem to do anything for me (though I’m likely just not understanding it). So that makes two questions now. Ugh, this stuff is giving me a headache lol.

Hey guys.
I’ve faced the same problem today when I was trying to make high resolution screenshot of my whole level from the very top of it. My smoke particles disappeared when I put my camera too far from the emitters. Problem was successfully fixed by increasing of value “View Distance” to 50000. This setting is placed in section “Volumetric Fog” of Exponential Height Fog actor (I guess you have this one on your level as well). Note, scroll bar can set 10000 only, but you can set bigger value in input manually.
Hope this will help :wink: