Hello,
I am having issues where my reflections are including objects in the foreground as seen in the image. It seems like this would be caused by screen space reflections but my reflection method is Lumen in post processing and I have enabled hardware raytracing reflections in Project Settings. Any Ideas? Thank you
Lumen, along with most raytracing, still relies on screen space effects for certain things. You can disable the screen traces if you want, but this will have some other visual impacts.
Can I disable just for those objects? So they dont cast reflections? Cus it dosent make sense visually that they reflect in the water in the distnace
that’s not possible, rn. screentraces literally take all of the things that are on screen.
argueably the geometry could be depth tested and not reflect what’s closer to the camera. bit of a hussle, programmatically. the water is clearly behind. the reflection vector points into the depth of the scene. not sure how exactly it traces but at some point it should hit the cloth and figure out it’s behind in the depth buffer. the lenght of the traces is the tricky part. ssr with obscuring and obscured objects are really not easy.
I made a super simple test case here which may be the same issue? Is there a way to fix this?
Super simple scene - raytracing on, lumen on, a bunch of cubes, one of which is reflective, and a light - and the foreground object wrong occludes a light visible in the background but only in the reflection. Is there a fix for this? Reflections are definitely set to lumen and not screen space (and in any case you can see that it’s not actually reflecting the blue stick - it’s more like a “shadow”).
Hmm thanks for the test. In the cast its more of a shadow instead of a reflection, wondering How I can get rid of it… I could disable shadow but then I wouldnt get the proper shadow in the foreground as it should be
I think my render artifact is different from yours - I’ve narrowed down what it is but don’t know how to fix it - I’ll start a different thread. Good luck!
The part of the background cube that is obscured by the blue stick - but visible in the reflection - is creating a discontinuity in screen tracing vs ray tracing.
Basically, in a scene like that (where reflections are mostly of objects that are on screen), screen tracing is doing 99% of the work. There will be a few spots where a screen trace is not possible (like behind the stick), so when a reflection of somewhere behind the stick is shown, it must be raytraced instead.
If there is any visual difference between the screen trace, and the raytrace, a discontinuity will be seen.
I’d suggest toggling screen tracing on and off to get a sense for how the scene may differ in one view or another, and how you can align them more closely.
Ideally, the raytraced scene will be shaded in a manner that is extremely close to the screen trace, but this is not always possible (because of resolution, for example, or assets that are not included in ray tracing at this time (such as decals)).
did you ever manage to fix this issue? i am having this issue
Not sure if related, but I have an issue of reflective surfaces casting light on geometry behind the surface. Is this just a limitation of lumen?
Probably same. Lumen GI has screen traces. You can disable them in the PPV to see if it helps.
Can you please explain the procedure to avoid this issue
Thanks in advance
