To declare shaderA program that runs on the GPU. More info
See in Glossary keywords, use a #pragma directive in the HLSL code. For example:
#pragma shader_feature REFLECTION_TYPE1 REFLECTION_TYPE2 REFLECTION_TYPE3
Use one of the following shader directives:
dynamic_branch to keep branching code in one compiled shader program.multi_compile or shader_feature to compile multiple shader variants, which means there’s a separate shader program for each branch.For information about when to use which shader directive, refer to How Unity compiles branching shaders.
If a shader uses more than 128 keywords in total, your project might be slower. As a result, it’s best to keep the number of keywords low. The total number of keywords include 4 keywords per shader that Unity always reserves.
The keywords in a single #pragma statement are together called a set.
For example, to declare a set of three keywords:
#pragma shader_feature REFLECTION_TYPE1 REFLECTION_TYPE2 REFLECTION_TYPE3
You can declare multiple sets of keywords in a single shader. For example, to create two sets:
#pragma shader_feature REFLECTION_TYPE1 REFLECTION_TYPE2 REFLECTION_TYPE3
#pragma shader_feature RED GREEN BLUE WHITE
You can’t do the following:
dynamic_branch and shader_feature or multi_compile. Unity uses dynamic_branch if you do this.At runtime, Unity has no concept of sets. You can enable or disable any keyword independently. As a result, it’s possible to enable two or more keywords from the same set at the same time, or disable all the keywords.
If you use shader_feature and enable multiple keywords from the same set, Unity tries to find the shader variant that most closely matches. This can lead to unintended results.