ShaderLab: defining a SubShader

To define a SubShader in ShaderLab, you use a SubShader block. This page contains information on using SubShader blocks.

For information on how a Shader object works, and the relationship between Shader objects, SubShaders and Passes, see Shader objects introduction.

Overview

A Shader object contains one or more SubShaders. SubShaders let you define different GPU settings and shader programs for different hardware, render pipelines, and runtime settings. Some Shader objects contain only a single SubShader; others contain multiple SubShaders to support a range of different configurations.

Render pipeline compatibility

Using the SubShader block

In ShaderLab, you define a SubShader by placing a SubShader block inside a Shader block.

Inside the SubShader block, you can:

• Assign a LOD (level of detail) value to the SubShader, using the LOD block. See assigning a LOD value to a SubShader.
• Assign key-value pairs of data to the SubShader, using the Tags block. See ShaderLab: assigning tags to a SubShader.
• Add GPU instructions or shader code to the SubShader, using ShaderLab commands. See ShaderLab: using commands.
• Define one or more Passes, using the Pass block. See ShaderLab: defining a Pass.
• Specify package requirements using the PackageRequirements block. This makes Unity only run the SubShader if the required packages are installed. See ShaderLab: specifying package requirements.

Examples

This example code demonstrates the syntax for creating a Shader object that contains a single SubShader, which in turn contains a single Pass.

Shader "Examples/SinglePass"
{
    SubShader
    {
        Tags { "ExampleSubShaderTagKey" = "ExampleSubShaderTagValue" }
        LOD 100

         // ShaderLab commands that apply to the whole SubShader go here. 

        Pass
        {                
              Name "ExamplePassName"
              Tags { "ExamplePassTagKey" = "ExamplePassTagValue" }

              // ShaderLab commands that apply to this Pass go here.

              // HLSL code goes here.
        }
    }
}