ShaderLab command: Offset

Sets the depth bias on the GPU.

Depth bias, also called depth offset, is a setting on the GPU that determines the depth at which it draws geometry. Adjust the depth bias to force the GPU to draw geometry on top of other geometry that is at the same depth. This can help you to avoid unwanted visual effects such as z-fighting and shadow acne.

To set the depth bias for specific geometry, use this command or a RenderStateBlock. To set the global depth bias, which affects all geometry, use CommandBuffer.SetGlobalDepthBias. The GPU applies the depth bias for specific geometry in addition to the global depth bias.

To reduce shadow acne, you can achieve a similar visual effect with the light bias settings; however, these settings work differently, and they do not change the state on the GPU. For more information, see Shadow troubleshooting.

Render pipeline compatibility

Feature name	Built-in Render Pipeline	Universal Render Pipeline (URP)	High Definition Render Pipeline (HDRP)	Custom SRP
Offset	Yes	Yes	Yes	Yes

Usage

This command makes a change to the render state. Use it in a Pass block to set the render state for that Pass, or use it in a SubShader block to set the render state for all Passes in that SubShader.

Signature	Example syntax	Function
`Offset <factor>, <units>`	`Offset 1, 1`	Draw geometry closer to or further away from the camera, based on the given values.

Valid parameter values

Parameter	Value	Function
factor	Float, range –1 through 1.	Scales the maximum Z slope, also called the depth slope, to produce a variable depth offset for each polygon. Polygons that are not parallel to the near and far clip planes have Z slope. Adjust this value to avoid visual artifacts on such polygons.
units	Float, range –1 through 1.	Scales the minimum resolvable depth buffer value, to produce a constant depth offset. The minimum depth resolvable depth buffer value (one unit) varies by device. A negative value means that the GPU draws the polygon closer to the camera. A positive value means that the GPU draws the polygon further away from the camera.

Examples

This example code demonstrates the syntax for using this command in a Pass block.

Shader "Examples/CommandExample"
{
    SubShader
    {
         // The rest of the code that defines the SubShader goes here.

        Pass
        {    
              // Sets the depth offset for this geometry so that the GPU draws this geometry closer to the camera
              // You would typically do this to avoid z-fighting
              Offset -1, -1

              // The rest of the code that defines the Pass goes here.
        }
    }
}

This example code demonstrates the syntax for using this command in a SubShader block.

Shader "Examples/CommandExample"
{
    SubShader
    {
         // Sets the depth offset for this geometry so that the GPU draws this geometry closer to the camera
         // You would typically do this to avoid z-fighting
          Offset -1, -1

         // The rest of the code that defines the SubShader goes here.        

        Pass
        {    
              // The rest of the code that defines the Pass goes here.
        }
    }
}

ShaderLab command: Cull

ShaderLab command: Stencil