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Zero width assets and GI,PL

Discussion in 'Global Illumination' started by konsic, Jan 10, 2020.

  1. konsic

    konsic

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    Is it better to create zero width assets or with assets with thickness when using progressive lightmapper baked indirect and realtime GI in HDRP?

    Assest which have thickness would theoretically produce more lightmaps and longer build. Is that correct?
     
    konsic, Jan 10, 2020
    #1

  2. AcidArrow

    AcidArrow

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    Depends on the scene.
     
    AcidArrow, Jan 10, 2020
    #2

  3. konsic

    konsic

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    How do you mean ?
     
    konsic, Jan 10, 2020
    #3

  4. iamthwee

    iamthwee

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    I always thought you NEEDED thickness to prevent light bleeding issues. That being said I don't intend to bake LMs anytime soon again lol .
     
    Last edited: Jan 10, 2020
    iamthwee, Jan 10, 2020
    #4

  5. konsic

    konsic

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    If I don't use faces which are infinitely close, then lightmaps should be smaller in size, right ?
    u2.JPG
     
    konsic, Jan 10, 2020
    #5

  6. AcidArrow

    AcidArrow

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    That's mostly for real time lights. For completely baked stuff, it's better without thickness, but again depends on the setup.

    The best compromise is to model single sided face for the interiors and then enclose that whole environment with some dummy geometry that is there only to cast shadows and avoid bleeding and is set as static with a lightmap scaling of 0.
     
    AcidArrow, Jan 10, 2020
    #6

  7. iamthwee

    iamthwee

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    In my tests it doesn't matter . . . planes without thickness cause light bleeding issues regardless if they are seemless.

    Well last time I tried enlighten. . .
     
    iamthwee, Jan 10, 2020
    #7

  8. AcidArrow

    AcidArrow

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    I'm not talking about enlighten (and I'm assuming konsic isn't either)
     
    AcidArrow, Jan 10, 2020
    #8
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  9. iamthwee

    iamthwee

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    hmm interesting, never knew that.
     
    iamthwee, Jan 10, 2020
    #9

  10. konsic

    konsic

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    PL = progressive lightmapper
     
    konsic, Jan 10, 2020
    #10

  11. uy3d

    uy3d

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    If you need a lightmap texture on both sides, then you'll need to use a thick mesh. Otherwise, you only have one set of UV coordinates and there's no way to store different lightmap information for either side.
    If you just need the geometry as a blocker that contributes to the GI calculations, but doesn't need a lightmap, you can use thin geometry, in most cases with a double sided material to avoid invalid ray queries.
    You can also setup thin geometry and only light it via probes now, but you'll need a current version of the editor for this feature.
     
    uy3d, Jan 13, 2020
    #11

  12. konsic

    konsic

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    In order to use it, I need to set geometry to static and in every mesh panel switch from lightmaps to light probes?
     
    konsic, Jan 13, 2020
    #12

  13. uy3d

    uy3d

    Unity Technologies

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    There's a blog post about how this feature works.
     
    uy3d, Jan 14, 2020
    #13