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HDRP Transparent Render Target Render Texture

Discussion in 'High Definition Render Pipeline' started by fffMalzbier, Aug 6, 2019.

  1. fffMalzbier

    fffMalzbier

    Joined:
    Jun 14, 2011
    Posts:
    2,797
    Dear unity Community / Unity Team.

    Im in need of a kind of special case withe the HDRP.

    I have a project that requires rendering a image of an object / scene with alpha channel in a RenderTexture.
    The original project was in unity 2018.2.16 with HDRP 3.0.0-preview and Post Processing 2.0.13-Preview.
    The RenderTexture did look like this:
    Color:
    screenshot.78.jpg
    Alpha:
    screenshot.77.jpg

    But in the current HDRP for 2019.1 / 2019.2 the alpha channel is allays just blank.

    Is there any way to recreate this result in a current unity / HDRP version?

    I do not need camera stacking , i do the compositing with other textures myself.
     
  2. gino_pisello

    gino_pisello

    Joined:
    Jun 24, 2013
    Posts:
    23
    i got a similar issue, hope anybody can help
     
  3. MS80

    MS80

    Joined:
    Mar 7, 2014
    Posts:
    335
    Same issue here, no alphachannel in RenderTexture with HDRP (Unity 2019.2.0f1).
    Hope this will be fixed, soon!?
     
  4. fffMalzbier

    fffMalzbier

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    Jun 14, 2011
    Posts:
    2,797
  5. MS80

    MS80

    Joined:
    Mar 7, 2014
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    335
  6. iSinner

    iSinner

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    Dec 5, 2013
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    As a work around you could render the alpha channel into a separate texture.
     
  7. fffMalzbier

    fffMalzbier

    Joined:
    Jun 14, 2011
    Posts:
    2,797
    Show me how.
    The Renderpipline is not rendering the alpha channel at all, so i do not have access to it.
     
  8. iSinner

    iSinner

    Joined:
    Dec 5, 2013
    Posts:
    128
    Oh, i thought you were controlling the rendering process.

    In this case i think this would require to fiddle with the rendering pipeline code itself, but i haven't done it so i can't suggest anything.

    This looks like a serious problem for devs if there aren't any available options to obtain the alpha channel for now, i hope Unity will add such an option in the future.