Pass tags in ShaderLab reference

Important: The Built-In Render Pipeline is deprecated and will be made obsolete in a future release.
It remains supported, including bug fixes and maintenance, through the full Unity 6.7 LTS lifecycle.
For more information on migration, refer to Migrating from the Built-In Render Pipeline to the Universal Render Pipeline and Render pipeline feature comparison.

This page contains information on using a Tags block in your ShaderLab code to assign tags to a Pass. It also contains information on using the LightMode tag, which determines when Unity runs the pass during rendering.

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

Render pipeline compatibility

Feature name	Universal Render Pipeline (URP)	High Definition Render Pipeline (HDRP)	Custom SRP	Built-in Render Pipeline
ShaderLab: Pass Tags block	Yes	Yes	Yes	Yes
ShaderLab: LightMode Pass tag	Yes	Yes	Yes	Yes

Syntax

Signature	Function
`Tags {"<name1>" = "<value1>" "<name2>" = "<value2>"}`	Applies the given tags to the Pass. You can define as many tags as you like.

LightMode tag

Signature	Function
“LightMode” = “[value]”	Sets the LightMode value for this Pass.

The LightMode tag determines when Unity executes the pass.

Valid values for this tag depend on the render pipeline. For more information, refer to:

PassFlags tag

In the Built-in Render Pipeline, use the PassFlags Pass tag to specify what data Unity provides to the Pass.

Value	Function
OnlyDirectional	Valid only in the Built-in Render Pipeline, when the rendering path is set to Forward, in a Pass with a `LightMode` tag value of `ForwardBase`. Unity provides only the main directional light and ambient/light probe data to this Pass. This means that data of non-important lights is not passed into vertex-light or spherical harmonics shader variables. See Forward rendering path for details.

Example

Shader "Examples/ExamplePassFlag"
{
    SubShader
    {
        Pass
        {    
              Tags { "LightMode" = "ForwardBase" "PassFlags" = "OnlyDirectional" }
            
              // The rest of the code that defines the Pass goes here.
        }
    }
}

RequireOptions tag

In the Built-in Render Pipeline, the RequireOptions Pass tag enables or disables a Pass based on project settings.

Value	Function
`SoftVegetation`	Render this Pass only if QualitySettings-softVegetation is enabled.

Additional resources

Configure if or when Unity uses a shader

Name directive in ShaderLab reference

Shader code blocks in ShaderLab reference