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Help Wanted URP Lit Particles - without self shadow

Discussion in '2021.2 Beta' started by SniperED007, Sep 3, 2021.

  1. SniperED007

    SniperED007

    Joined:
    Sep 29, 2013
    Posts:
    250
    Is there a way to turn off self-shadowing on particles?
    I have alpha lit particles that I don't want to look dark if the direction light is coming from behind the particles, only want them to be dark if they are in the shadow of objects.
     
  2. pez

    pez

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    Jul 6, 2013
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    I might be misunderstanding the question, but you can disable shadow casting from the particles themselves in the particle system renderer settings - https://i.imgur.com/oyO4LZb.png
     
  3. richardkettlewell

    richardkettlewell

    Unity Technologies

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    If they are billboards, maybe changing the Normal Direction in the Renderer module may help.
     
  4. SniperED007

    SniperED007

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    Sep 29, 2013
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    To explain it better:
    this is looking at the particles and it looks great... but when I view it from behind all the particles are black (I want the sunlight to pass through it so that it looks the same as the front)
    upload_2021-9-3_21-50-40.png

    The other view:
    upload_2021-9-3_21-52-2.png
     
  5. hippocoder

    hippocoder

    Digital Ape Moderator

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    Then you should add ambient light of some kind or adjust the shader so it is not necessary. Does the same happen if you add a regular mesh sphere? if so then you need to address it in the same way or modify the shader to your liking / use other shader.
     
  6. richardkettlewell

    richardkettlewell

    Unity Technologies

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    Adjusting the Normal Direction setting will definitely help wrap the lighting around the back of the billboards a bit more.

    But really you are probably wanting some sort of translucency/sub-surface scattering. HDRP has that but maybe not URP. I’m not sure.

    Hippocoder is right about needing a custom shader (graph) to try and do this. Ambient is a good cheap alternative.
     
    Last edited: Sep 4, 2021
  7. hippocoder

    hippocoder

    Digital Ape Moderator

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    Yep I just wanted to demystify what shader they might've been using - could be alpha cutout - I can't see, and I don't truly know their intention.
     
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