Hello everyone. I spent tens of hours trying to solve this problem, and finally came up with a solution. There is no solution what so ever online, so I figured I’d post it and hopefully help someone.
The problem was that the post processing (in our case outlines and cell shading) went straight over our particle effects and other translucent materials, which made it really ugly.
The solution to this problem is really really stupid: In your blueprint, create a static mesh component and activate “Render CustomDepth Pass”. Then move the particle emitter “below” the static mesh component in the components tab. Everything worked flawlessly after that.
It is seemingly impossible to do this directly in the particle system options, which is what I was trying to do for days.
Hope this helps, I will try to tag it so that it pops up on google.
Greetings,