Hello,
After light building in a quite large scene, we saw some strange artifacts that result from fireflies in the volume light samples.
See the two attached screenshots. What causes these issues and how can we resolve that movable meshes do not get strange lighting?
Also we have splotches on some of the static mesh walls in the same room. There seems to be some problem in the lighting calculations. Any info or help is appreciated.
Best regards,
Guido
BUMP BUMP. Anyone any ideas? 
Hey LeFxGuy -
Without the actual Lighting setup and level it is hard to diagnosis the issue form the images above, but I can make some suggestions to test. Since Volume Lighting Samples show how the indirect lighting in the level is functioning I might guess that some of these white “fireflies” are actually the reflection highlights off of objects in your level. Have you increased the intensity of your reflections in the level or added and increased the intensity of a sky light in your level? Also it may mean that you need an additional sphere reflection capture actor for a specific area because the reflected cube map is sampling something further away and applying it into the lighting in an area that it is not needed. As for the Static Mesh Wall issue that is probably something to do with your unwrap or Lightmap resolution, though the white highlights also suggest some reflections issues as well.
Try to adjust some of the setting above, but if you still cannot achieve the desired effect, I would need a sample project that has the same issue to determine the exact cause and find a solution for you.
Thank You
Eric Ketchum
Hello Eric,
First of all thank you very much for your detailed answer. Problem is that we cannot share the scene but we could get it resolved. The spotlights in question were placed too far into the lamp body and we also changed some values (inner spot angle for example). This fixed our problems and yes we also thought about strange reflections in the first place but could not find out what was causing this issue. For the wall: this was also not from our unwrap but also caused by the lights and some weird reflections. Now everything is solved. Thank you
