Particle Fog Volume?

I’m wondering if I can use a particle cube volume to simulate volumetric lighting? The steam_lit particle that comes with UE4 by default is sort of volumetric, in that it receives light and shadow, so when I placed one in my level and attached it to my character, light passing through like tree branches and stuff appeared like light shafts, but without having to look up at the light source and without having to place static meshes. (I’d really like it if the shafts were dynamic.) The problem is that the particle is essentially a series of planes that are spawning, but what I’m looking for is the ability to make an effect that is like a particle volume, so that if I put a cube in my worldspace, the material would take up the space inside the cube, rather than just being on the surfaces of it. Is this possible? I don’t really know a whole lot about the particle editor. Is a vector field something that could do this? If so, how would I go about making it?

yes you can do what you are talking about, which is basically placing slices of translucency to receive shadows. I have tried it before. It does work but the downside is that the shadow resolution for translucency is not that high so you may not get nice enough shadows for what you want, and also the more overdraw the more expensive. Less cards will be cheaper but will look less volumetric.

All you need is some particles to spawn inside of your cube and for them to be lit. You dont even need to use particle system. You could just take a simple sheet mesh and duplicate it a bunch inside of a cube to test it out. Put a lit translucent material on it and turn off shadow casting.

Thank you, can’t wait to try it out! Even if it’s not super precise, it’ll be a step in the right direction. Thanks so much!

Super low res, but it works!

How do I set up the fade distance from the camera position? I feel like that might kinda hide the fact that there are big spaces between each plane haha.

there is a material function already called “camera depth fade” that you can use. has controls for start offset and fade length etc.

Sweet, thanks! It’s coming along rather nicely now, at least for my purposes.



cool. you could probably make a BP that lets you tweak the spacing of the slices and/or convert them into sprites to give yourself some basic quality/performance controls. ie, more slices = better quality.

obviously a better solution will need code. lots of people (including us) are asking for that right now, but it still is probably a ways off. I am glad you are trying other solutions in the mean time.

Oh yeah, I’m happy with this for the time being, and I’m thankful for the amount of versatility in the engine already. Having volumetric stuff built in in he future would just be a welcomed bonus. Thanks (again) for your time, have a great day!