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Won't Fix

Votes

0

Found in

2022.3.61f1

6000.0.46f1

6000.1.0b14

6000.2.0a8

Issue ID

UUM-102343

Regression

No

Stencil WriteMask is null when using deferred pipeline

-

Reproduction steps:
1. Open the attached project "ReproProj"
2. Open the “/Assets/Scenes/SampleScene.unity” Scene
3. Enter the Play Mode
4. Notice how the silhouette of the "vehicle" is correctly rendered in the left camera (forward) and incorrect in the right camera (deferred)
5. Open Frame Debugger (Window > Analysis > Frame Debugger)
6. Look for the Camera.Render > Drawing where right car is shown in the Output
7. Observe the Stencil WriteMask

Expected result: The Sencil WriteMask is set to bit 5 (32)
Actual result: The Stencil WriteMask is null

Reproducible with: 2022.3.61f1, 6000.0.46f1 , 6000.1.0b14, 6000.2.0a8

Reproducible on:
Play Mode

Testing environment: Windows 10 Enterprise 21H2
Not reproducible on: No other environment tested

  1. Resolution Note:

    As mentioned in the documentation page linked below "Stencil functionality for objects rendered in the deferred rendering path is somewhat limited, as during the G-buffer pass and lighting pass, Unity uses the stencil buffer for other purposes. During those two stages, the stencil state defined in the shader will be ignored...": https://docs.unity3d.com/es/2021.1/Manual/SL-Stencil.html

    This leads to your `WriteMask 32` not being set properly during the G-Buffer (as visible in the FrameDebugger, it's overridden to the '207' value, which has bit 5 set to 0) and thus not writing the value you expect).

Comments (1)

  1. m43_daniel

    Apr 11, 2025 14:10

    The writemask is not null. It's set to an hardcoded value. Just like the ref is. The big difference is that the ref is or'ed with the value from the shader while the writemask is not. For some unknown reason.

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