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Question Different intensity with SSGI + Ray Tracing between Unity 2020 and 2022

Discussion in 'High Definition Render Pipeline' started by jsr2k1, Feb 22, 2023.

  1. jsr2k1

    jsr2k1

    Joined:
    Aug 11, 2010
    Posts:
    118
    Hello,

    We recently changed from Unity 2020.3.34 to 2022.2.5

    In our project, we use a Global Volume with SSGI + Ray Tracing. We also use Exposure with a fixed value and a Visual Environment with Sky Type None and Ambient Mode Static. We have noticed a difference in lighting, but the scene and parameters are exactly the same as you can see in the attached images.

    The HDRP Assets for 2020 and 2022 have the same configuration.

    Any idea why is this happening?

    test 2020.PNG test 2022.PNG

    params.PNG
     
  2. jsr2k1

    jsr2k1

    Joined:
    Aug 11, 2010
    Posts:
    118
    Screen Space Reflections has different behaviors also.
    As you can see in the attached images.

    Any suggestions?

    reflections 2020.PNG reflections 2022.PNG
     
  3. PutridEx

    PutridEx

    Joined:
    Feb 3, 2021
    Posts:
    1,136
    Possibly a bug, probably worth reporting it and posting the bug # here.
     
  4. jsr2k1

    jsr2k1

    Joined:
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    Or maybe is some parameter in the HDRP Asset configuration?
    I tried with a new scene in both 2020 and 2022 and looks like the lighting behavior is different.

    empty2020.PNG empty2022.PNG
     
  5. jsr2k1

    jsr2k1

    Joined:
    Aug 11, 2010
    Posts:
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    I've found the difference. SSGI works properly with Directional Lights, but fails with Area Lights.
    Indirect lighting is not being calculated with Area Lighs.

    Bug or HDRP configuration?

    directional light 2020.PNG directional light 2022.PNG
    area light 2020.PNG area light 2022.PNG
     
  6. jsr2k1

    jsr2k1

    Joined:
    Aug 11, 2010
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    This is fixed in Unity 2022.2.7!

    I was using 2022.2.5
     
    PutridEx likes this.
  7. jsr2k1

    jsr2k1

    Joined:
    Aug 11, 2010
    Posts:
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    The SSR + Ray Tracing problem still persists in this version.
    If I use a 'Bounce Count' greater than 1 then the reflections are blurry.

    Any idea?

    reflections 2020.PNG reflections 2022.PNG
     
  8. jsr2k1

    jsr2k1

    Joined:
    Aug 11, 2010
    Posts:
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    ok, in this case, the problem is 'Denoiser Radius' value was too large.
    If I set it to 1 then it works properly.

    By the way, do you know if it's possible to get indirect lighting coming from SSGI in the reflections from SSR ?
     
  9. chap-unity

    chap-unity

    Unity Technologies

    Joined:
    Nov 4, 2019
    Posts:
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    This is expected, it's because the denoiser doesn't affect smooth surfaces by default when bounce count is 1. When it gets above, we can't really know if the reflection inside the reflections is going to need denoiser or not, so we denoise even smooth surfaces which result is a slightly blurrier smooth surface (and you are right that this depends on the radius of the denoiser as well).