Question what is the parameter "render target" in the ShaderLab command "ColorMask" ?

in the document for ShaderLab ColorMask command, there is a parameter called render target which takes values between 0 and 7, what are those 8 render targets and how to use them?

 

Hi, I think it's for assigning different ColorMask when using Multiple Render Targets (MRT) feature.

One usage of MRT is the deferred rendering path, which usually uses MRT in fragment shader to fill all GBuffer textures in one pass.

Code (CSharp):

1. // Example from URP's Lit GBuffer shader pass
2.  
3. struct FragmentOutput
4. {
5.     half4 GBuffer0 : SV_Target0;
6.     half4 GBuffer1 : SV_Target1;
7.     half4 GBuffer2 : SV_Target2;
8.     half4 GBuffer3 : SV_Target3; // Camera color attachment
9.  
10.     #ifdef GBUFFER_OPTIONAL_SLOT_1
11.     GBUFFER_OPTIONAL_SLOT_1_TYPE GBuffer4 : SV_Target4;
12.     #endif
13.     #ifdef GBUFFER_OPTIONAL_SLOT_2
14.     half4 GBuffer5 : SV_Target5;
15.     #endif
16.     #ifdef GBUFFER_OPTIONAL_SLOT_3
17.     half4 GBuffer6 : SV_Target6;
18.     #endif
19. };
20.  
21. // fragment stage
22. FragmentOutput fragment(Varyings input)
23. {
24.     //...
25. }

 

Thanks for the clue <3