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(Case 1175234) Progressive lightmaper fails to produce usable result with some scene setups

Discussion in 'Global Illumination' started by liiir1985, Aug 12, 2019.

  1. liiir1985

    liiir1985

    Joined:
    Jul 30, 2014
    Posts:
    147
    Hello, I've submit an issue about the progressive lightmapper recently, but the Unity QA Team had some problem to reproduce it so I think I'd better post it here again, so I can better explain it.

    So basically what I did is to put some object into the scene and then placed a plane over the ground to cover the area from the sun light to create different mood for some area of the scene, like below:


    But what we get with the progressive lightmaper is completely wrong and unusable, which is shown in the next screenshot:

    As you can see, there are many strange squres on the ground, indicated with the black arrows, and the edge of the shadow projected by the plane also has many zigzag aliasing, which is much more serious than it should be, please compare to shadow of the boxes. Also the roof of the house has abnormal black shadows, which shouldn't look like this.

    If I increase the size of the plane, it will look even worse, like this:


    This issue should be reproduced easily with the project I submit along with the issue, because I get the same result regardless where I bake this scene, I tried this sample on several computers, and they show the same result
     
    Last edited: Aug 12, 2019
  2. KEngelstoft

    KEngelstoft

    Unity Technologies

    Joined:
    Aug 13, 2013
    Posts:
    1,366
  3. liiir1985

    liiir1985

    Joined:
    Jul 30, 2014
    Posts:
    147
    I Don't think it has anything to do with the uv overlapping, because even if I delete all the objects I placed, just leaving 2 planes, the problem still exists, like below:


    PS: Increasing Pack margin won't help with the uv overlapping issue, even with the maximum value, they are still overlapping as before
     
  4. KEngelstoft

    KEngelstoft

    Unity Technologies

    Joined:
    Aug 13, 2013
    Posts:
    1,366
    That is because the plane is seeing only backfaces. Use double sided GI materials or set a lower backface tolerance using a Lightmap Parameters. The texel validity view will show you that you have a lot of invalid texels due to backfaces.
     
  5. liiir1985

    liiir1985

    Joined:
    Jul 30, 2014
    Posts:
    147
    Ah, thanks for the info, it indeed solve the problem.
    But it's strange that enlighten won't have this problem
     
  6. bluescrn

    bluescrn

    Joined:
    Feb 25, 2013
    Posts:
    642
    (d'oh, duplicate answer)