UE4 SubUV movie flickering when particle is scaled

Hi, guys!

I have this very simple particle effect on a game I’m working on that’s displaying just fine when the scale is the default (1.0 in the world object, and 3000 for XYZ in the Initial Size module of the particle). But when the particle is scaled, for example, to 4 or 5 in the world (or 12000 in the Initial Size module), it gets a flickering thing, like this on this GIF.

Does anyone know the cause and how to fix this? First time happening here and I’m not really a VFX artist, so any help appreciated! :slight_smile:

EDIT: Discovered it’s the Particle Cutout effect giving this artifact. Any way to minimize it?

A few thigs come to mind:
-It could be the bounds. Try manually upping the bounds of your particle system an see if that fixes it.
-Try different particle sorting methods (it might be overlapping particles that are z-fighting).
-It could also be that two particles are overlapping, in time. Like if the lifetime would be 1 and you are spawning a new particle every 1sec, there might be a slight overlap. You could prevent this by making the particle infinite lifetime instead.
-Similarly, it could be the flipbook, playing the first frame again after the last. You can prevent this by making the flipbook time go from 0-0.99, instead of 0-1.

Not sure why the particle cutout would cause this, does it not happen when not having a cutout, just the sprite? You could also try putting it on a mesh particle then, rather than a sprite.

Thanks for the suggestions, Tobias!
I’ve tried them but unfortunately didn’t work. :frowning:
The bigger the particle gets scaled, the more noticeable the flickering is. And yeah, without the particle cutout thing, it works perfectly, but I need it enabled to some extent to prevent overdraw. I increased the alpha value a little bit and it seems to work better (still noticeable flickers when too close, but the smoke is at a distance so I guess it’s fine).