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Unity 5.6 and shadow issues on Android

Discussion in 'Android' started by wildbean, Jun 7, 2017.

  1. wildbean

    wildbean

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    Hi all , my game has been running great even on old Android devices like Samsung Galaxy S3 , but I've found since upgrading Unity to 5.6 that the realtime shadows have degraded *dramatically*. The shadows now glitch and jump around - becoming very blocky, and actually get worse and worse the longer you spend playing the game. The framerate has tanked as a result it seems as well.

    I've confirmed this on several S3 and S3-Mini devices.

    However the game still runs perfectly fine on my Nexus 5, and all newer phones such as S6 / Nexus 5x / S8 that we have tested as well.

    Any ideas on what could be causing this, and possible solutions?
     
    wildbean, Jun 7, 2017
    #1

  2. florianpenzkofer

    florianpenzkofer

    Unity Technologies

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    Can you please create a bug report with repro case and post the case number here?
    Please mention the exact model number for Samsung devices and the Android version that you are running.

    What shader are you using?
    Does it maybe only happen with OpenGL ES 2.0?
     
    florianpenzkofer, Jun 7, 2017
    #2

  3. wildbean

    wildbean

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    Sure, thanks for the response. I'll do some more testing and come back with some more details for you.
     
    wildbean, Jun 8, 2017
    #3

  4. wildbean

    wildbean

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    I've done some more testing and submitted a bug report with repro case 919669.

    I was previously using a custom vertex color shader on my project , however even after creating a new simple test project for this bug report and using only basic cubes and Unity's built-in Mobile Diffuse shader I'm seeing this issue as demonstrated in the attached project.

    Hopefully you can shed some light on this for me! Thanks

    *edit* Oh one other thing - I forgot to mention in the bugreport that the Android Version on the S3 (GT-I9300) is Android 4.3.
     
    wildbean, Jun 10, 2017
    #4

  5. florianpenzkofer

    florianpenzkofer

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    QA closed the case as a duplicate of case https://issuetracker.unity3d.com/is...ing-away-from-world-origin-on-older-mali-gpus. But thanks for reporting, I think your repro project might still be useful.

    We didn't really look into the problem yet, but it all sounds like shader precision issues. afaik Mali 400 varyings and fragment shaders are lower precision than most others (basically only what the OpenGL ES 2 or GLSL ES 1.0 spec mandates for mediump).
     
    florianpenzkofer, Jun 13, 2017
    #5

  6. wildbean

    wildbean

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    Ok sure, hope my report helps.

    Any pointers on how I could workaround this, as obviously using standard shaders on my mobile game is not going to work for me, and I imagine it's not yet known when that bug will be fixed? I was aiming to launch very soon before I hit this issue.

    *edit*
    Also, does the fact that it worked fine for my project on 5.5.2f1 give us anything else to go on do you think?

    I notice the existing bug 908253 has a severity of 3, and when I mouseover that number it says a workaround is possible. Can you point me to where I could find a known workaround by any chance? Thanks
     
    Last edited: Jun 14, 2017
    wildbean, Jun 13, 2017
    #6

  7. florianpenzkofer

    florianpenzkofer

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    We figured out that the regression was introduced in Unity 5.6. The calculation of the shadow coordinate was moved to the fragment shader (for shadow masking).
    But using world coordinates on a GPU that can only do mediump in the fragment shader doesn't really work.
    We are working on a fix.

    I can't think of a simple workaround other than modifying the shaders accordingly.
     
    florianpenzkofer, Jun 15, 2017
    #7

  8. wildbean

    wildbean

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    Hi again, I see that bug now has a status of "Fixed in future release" - out of interest is it known (or visible anywhere) what specific version it will be fixed in, so as I can decide on my best course of action? Thanks
     
    wildbean, Jun 23, 2017
    #8

  9. florianpenzkofer

    florianpenzkofer

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    Since this is a regression that appeared in 5.6 we will try to backport the fix to 5.6.
     
    florianpenzkofer, Jun 23, 2017
    #9

  10. wildbean

    wildbean

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    Ok great thanks. Does this essentially mean that version 5.6.3f1 would have it? Or any rough ETA on when it might happen?
     
    wildbean, Jun 24, 2017
    #10

  11. florianpenzkofer

    florianpenzkofer

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    I hope it will be fixed in a patch release until 5.6.3f1, but not guaranteed. It is not a trivial fix and requires changes to Surface Shader code generation and shader includes.
     
    florianpenzkofer, Jun 26, 2017
    #11

  12. wildbean

    wildbean

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    Well I've just tested and my bug is still present in Unity 2017.2 version.
     
    wildbean, Dec 19, 2017
    #12