Hi!
Any ideas how to get rig of this ghosting? So far my only solution is to change GI method to other than Lumen.
You can increase the speed which lumen updates but this will increase the performance cost. Lumen, like most raytracing solutions, used data accumulated over multiple frames to improve quality without needing large numbers of samples per frame.
The side effects of this is rapid changes in lighting will ghost.
I’ll add on that: Niagara sprites are currently only inserted into lumen via screen-space (to my knowledge). if you turn lumen.screenprobegather.screentraces to 0, it should fix the effect, while also removing any diffuse screen-space lighting for you.