Fallback block in ShaderLab reference

This page contains information on using a Fallback block in your ShaderLabUnity’s language for defining the structure of Shader objects. More info
See in Glossary code to assign a fallback ShaderA program that runs on the GPU. More info
See in Glossary object. For information on how a Shader objectAn instance of the Shader class, a Shader object is container for shader programs and GPU instructions, and information that tells Unity how to use them. Use them with materials to determine the appearance of your scene. More info
See in Glossary works, and how Unity chooses when to use a fallback, see Shader objects introduction.

Render pipeline compatibility

Feature name	Universal Render PipelineA series of operations that take the contents of a Scene, and displays them on a screen. Unity lets you choose from pre-built render pipelines, or write your own. More info See in Glossary (URP)	High Definition Render Pipeline (HDRP)	Custom SRP	Built-in Render Pipeline
ShaderLab: Fallback block	Yes	Yes	Yes	Yes

Syntax

To assign a fallback, you place a Fallback block inside a Shader block.

Signature	Function
`Fallback "<name>"`	If no compatible SubShaders are found, use the named Shader object.
`Fallback Off`	Do not use a fallback Shader object in place of this one. If no compatible SubShaders are found, display the error shader.

Example

This example code demonstrates the syntax for creating a Shader object that has a named fallback.

Shader "Examples/ExampleFallback"
{
    SubShader
    {
        // Code that defines the SubShader goes here.

        Pass
        {                
              // Code that defines the Pass goes here.
        }
    }

    Fallback "ExampleOtherShader"
}

Properties block reference in ShaderLab

Custom Editor block in ShaderLab reference