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Won't Fix

Votes

0

Found in

2021.3.40f1

2022.3.37f1

6000.0.10f1

6000.0.15f1

Issue ID

UUM-75751

Regression

No

GameObject Alpha Clipping does not work when a ShaderGraph Material is assigned during runtime

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How to reproduce:
1. Open the “Material.zip“ project
2. Open the “SampleScene“
3. Observe the Plane GameObject in the Game view
4. Enter Play Mode
5. Press the Enter key
6. Observe the Plane GameObject in the Game view

Expected result: The Plane GameObject is still Alpha Clipped
Actual result: The Plane GameObject is not Alpha Clipped anymore

Reproducible in: 2021.3.40f1, 2022.3.37f1, 6000.0.10f1

Reproduced on: Windows 11 Pro (23H2)
Not reproduced on: No other environment tested

Note: Reproducible in the Player

  1. Resolution Note:

    I was able to reproduce the issue locally. It's a known limitation of the Material system :

    - When you change a Material’s properties in the Inspector, the Render Pipeline sets up properties, keywords, and passes on the Material directly so that it can be rendered correctly.

    - When you instantiate a Material in C# (e.g new Material(mShader)), the Keywords are not updated automatically or set. So in this bug report, the Alpha Clipping is not enabled automatically after instantiating the Material.

    - To fix it, you need to change a property of the Material from the inspector directly (like the Alpha Clipping one) so the Keywords are updated. 

    This is not a new limitation, but a pretty old one. We don't have a system, like a callback system, to automatically update the Keywords, since instantiating a Material (with the new keyword) is at the barebone of our system and not something we can overload. 

    Since this is not a very common case, the workaround for the users would be to manually change the Keywords on the Material after instantiating it, by using EnableKeyword. 

    HDRP has this custom solution, which is to call the HDRP function ValidateMaterial after instantiating it: https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@15.0/manual/Material-API.html

    URP doesn't have an equivalent. 

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