I’m using 5.2 Preview 2 to test out what’s new in the world of UE Path Tracing. One thing I still don’t see is the ability to turn off light visibility in refractions.
In the example here, I have a skylight with an HDRI piped in, as well as a rect light. They are invisible, except for when they are seen through a mesh with a glass material on it.
In other offline renderers, such as VRay, simply turning “Affect Refractions” off for that light would solve this problem.
Turning off Specular and Indirect Specular removes the light visibility, but this affects the render scene-wide, hiding the light’s reflection entirely, which is undesirable.
It seems both reflections and refractions are combined in this Specular attribute.
Are there any plans to separate reflections and refractions? Also, are there plans to shift these settings from the Post Process Volume to the individual lights? That would be the most useful!
For lights, we can probably use light channels, to mitigate this (im not sure though), but for HDRI this is really annoying.
I have found some workarounds though, but not a strong solution.
you would probably want to try these below suggestions for your glass render only and comp it over your original render.
solution 1: Limit the number of light Rays to 3 or 2 in post process.
solution 2: r.PathTracing.MISMode 1 to remove HDRI reflections on glass. (2 is default)
There are many obvious things that the Engine still lacks or available to do only through a very technical workaround.
I really hope Epic addresses feature requests like these.
