Search Unity

  1. Unity Asset Manager is now available in public beta. Try it out now and join the conversation here in the forums.
    Dismiss Notice
  2. Megacity Metro Demo now available. Download now.
    Dismiss Notice
  3. Unity support for visionOS is now available. Learn more in our blog post.
    Dismiss Notice

Question Questions about raytracing and reflections with transparency and emission maps

Discussion in 'HDRP Ray Tracing' started by AStickInTheMud, Feb 26, 2021.

  1. AStickInTheMud

    AStickInTheMud

    Joined:
    Feb 15, 2019
    Posts:
    4
    I was playing around with the HDRP raytracing and was quite impressed. Reflections seem to be accurate, and the performance is stable for this little scene I made.



    In it there is 4 perfectly smooth black walls, a cube of the same material, a smooth emissive circuitboard patterned floor and ceiling, one emissive red cube, one emissive nested blue cube inside a nonsmooth translucent cube, and an emissive translucent cube with a gradient base map and emission map.



    The first question I had was why the reflection of the nested cube does not display the same blur around the light source as directly looking into the cube? I assume this has something to do with how the ray is traced from the screen space to the light source and not checked for refraction during a second pass? Would there be a way to force another shader or postprocess effect on the refelection?



    The other question I had is why the translucent emissive cube does not seem to be redered in reflections at all. My best guess is that currently emissive translucent materials are not supported in the realtime raytracer? If someone could enlighten me about the specifics of the mechanics of this I would appreciate it.




    As a side note, without the "Transparent depth prepass" checked, the backfaces are improperly sorted, while with it checked the backfaces are not rendered at all. To my uderstanding this is an unsolved issue with rendering backfaces of transparent objects in general, though I thought using a ray tracer would be able to properly sort the faces by virtue of how the path is traced?