Shader renders whole texture when 'default' is uncommented in 'switch' statement in a script

Unity: Metal

Won't Fix

6.6.X

6.5.X

6.4.X

6.3.X

6.0.X

2023.2.X

This looks like the issue with the "speculative execution" when GPU runs both branches and then somehow selects the correct one. The issue can be easily fixed (and there is a clear warning in shader inspector) by initializing texColor variable explicitly before the switch (or, indeed, adding default: case).

How to reproduce:
1. Open the “Broken Shader“ project
2. Open the “SampleScene“ scene
3. Make sure build profile is iOS
4. Navigate to Project section and open /Assets/CoolBrokenShader.shader
5. On line 82 uncomment the “default:“ value
6. Enter Play mode
7. Observe the result

Actual result: Whole texture is rendered with triangles
Expected result: Only a certain part is rendered with triangles

Reproducible with: 2023.2.0a9, 6000.0.69f1, 6000.3.10f1, 6000.4.0b10, 6000.5.0a7
Could not test with: 2023.1.0a1 (Shader errors)

Reproducible environment: macOS 26.3 (M1 Max)
Not reproducible environment: No other environments tested

Note: This issue does not occur on macOS/Windows build profile

Shader renders whole texture when 'default' is uncommented in 'switch' statement in a script

Unity: Metal

Won't Fix

Prioritise and Follow this issue

Have a workaround or additional info about this issue?

Shader renders whole texture when 'default' is uncommented in 'switch' statement in a script

Unity: Metal

Statuses

Won't Fix

Resolution Notes

Description

Prioritise and Follow this issue

Have a workaround or additional info about this issue?