Version: 2021.3
ShaderLab command: Blend
ShaderLab command: ColorMask

ShaderLab command: BlendOp

Specifies the blending operation used by the Blend command. For this command to have any effect, there must also be a Blend command in the same Pass block (if this command is in a Pass block) or SubShader block (if this command is in a SubShader block).

Not all blending operations are supported on all devices, and support depends on both the graphics API and the hardware. Different graphics APIs handle unsupported blending operations differently: GL skips unsupported operations, and Vulkan and Metal fall back to Add operations.

Render pipeline compatibility

Feature name Built-in 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
Universal Render Pipeline (URP) High Definition Render Pipeline (HDRP) Custom SRP
BlendOp 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
BlendOp <operation> BlendOp Sub Sets the blending operation used by the Blend command.

Valid parameter values

Parameter Value Function
operation Add Add source and destination together.
Sub Subtract destination from source.
RevSub Subtract source from destination.
Min Use the smaller of source and destination. (See note 1)
Max Use the larger of source and destination. (See note 1)
LogicalClear Logical operation: Clear (0) (See note 2)
LogicalSet Logical operation: Set (1) (See note 2)
LogicalCopy Logical operation: Copy (s) (See note 2)
LogicalCopyInverted Logical operation: Copy inverted (!s) 2
LogicalNoop Logical operation: Noop (d) (See note 2)
LogicalInvert Logical operation: Invert (!d) (See note 2)
LogicalAnd Logical operation: And (s & d) (See note 2)
LogicalNand Logical operation: Nand !(s & d) (See note 2)
LogicalOr Logical operation: Or (s | d) (See note 2)
LogicalNor Logical operation: Nor !(s | d) (See note 2)
LogicalXor Logical operation: Xor (s ^ d) (See note 2)
LogicalEquiv Logical operation: Equivalence !(s ^ d) (See note 2)
LogicalAndReverse Logical operation: Reverse And (s & !d) (See note 2)
LogicalAndInverted Logical operation: Inverted And (!s & d) (See note 2)
LogicalOrReverse Logical operation: Reverse Or (s | !d) (See note 2)
LogicalOrInverted Logical operation: Inverted Or (!s | d) (See note 2)
Multiply Advanced OpenGL blending operation: Multiply (See note 3)
Screen Advanced OpenGL blending operation: Screen (See note 3)
Overlay Advanced OpenGL blending operation: Overlay (See note 3)
Darken Advanced OpenGL blending operation: Darken (See note 3)
Lighten Advanced OpenGL blending operation: Lighten (See note 3)
ColorDodge Advanced OpenGL blending operation: ColorDodge (See note 3)
ColorBurn Advanced OpenGL blending operation: ColorBurn (See note 3)
HardLight Advanced OpenGL blending operation: HardLight (See note 3)
SoftLight Advanced OpenGL blending operation: SoftLight (See note 3)
Difference Advanced OpenGL blending operation: Difference (See note 3)
Exclusion Advanced OpenGL blending operation: Exclusion (See note 3)
HSLHue Advanced OpenGL blending operation: HSLHue (See note 3)
HSLSaturation Advanced OpenGL blending operation: HSLSaturation (See note 3)
HSLColor Advanced OpenGL blending operation: HSLColor (See note 3)
HSLLuminosity Advanced OpenGL blending operation: HSLLuminosity (See note 3)

Notes:

  1. Min and Max require GL_EXT_blend_minmax on OpenGL ES 2.
  2. Logical operations require DX 11.1+ or Vulkan.
  3. Advanced OpenGL blending operations require GLES3.1 AEP+, GL_KHR_blend_equation_advanced, or GL_NV_blend_equation_advanced. They can only be used with standard RGBA blending; they are not compatible with separate RGB and alpha blending.

Examples

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

        Pass
        {    
             // Enable subtractive blending for this Pass
             Blend SrcAlpha One
             BlendOp RevSub
            
              // 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
    {
         // Enable subtractive blending for this SubShader
         Blend SrcAlpha One
         BlendOp RevSub

         // 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: Blend
ShaderLab command: ColorMask