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Fixed in 2023.3.0b7



Found in


Issue ID




"maximum ps_4_0 sampler register index (16) exceeded" error is thrown on build when enabling LOD Cross-Fade



How to reproduce:
1. Open the attached project “Test”
2. Build And Run the project

Expected result: The project is successfully built
Actual result: The project building fails with the "maximum ps_4_0 sampler register index (16) exceeded" error

Reproducible with: 2022.3.7f1
Couldn’t test with: 2021.3.29f1, 2023.1.8f1, 2023.2.0b4 (The project becomes broken after changing the version)

Reproducible on: Windows 11 Pro
Not reproducible on: No other environment tested

  1. Resolution Note (fix version 2023.3.0b7):

    This error is a hard limit from the graphics API and cannot be fixed or changed. Direct3D 11 supports only 16 active texture samplers in one shader. Unity creates a sampler per texture due to historical reasons. The solution is to reduce the number of textures used by the shader. Alternatively the samplers can be shared using hardcoded inline samplers (excluding OpenGL).

    The bug is marked fixed. The fix turns several internal samplers into shared inline samplers. While this won't fix the underlying issue (limit of the graphics API and/or hardware), it should reduce the likelihood of hitting this limit.
    If you hit this limit again, try to reduce the enabled textures or features in the (Lit) shader to workaround the issue.

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