Writing vertex and fragment shaders

ShaderLabUnity’s declarative language for writing shaders. More info
See in Glossary shaders describe properties that the Material InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, alowing you to inspect and edit the values. More info
See in Glossary displays, contain multiple shaderA small script that contains the mathematical calculations and algorithms for calculating the Color of each pixel rendered, based on the lighting input and the Material configuration. More info
See in Glossary implementations for different graphics hardware, and configure fixed function hardware states. Programmable shaders like vertex and fragment programs, are just a part ShaderLab’s shader concept. For more information and an introduction on shaders, see the shader tutorial. This page outlines the low-level hardware shaders shader programs.

If you want to write shaders that interact with lighting, see the Surface ShadersUnity’s code generation approach that makes it much easier to write lit shaders than using low level vertex/pixel shader programs. More info
See in Glossary documentation. For some examples, see the Vertex and Fragment Shader Examples. The rest of this page assumes shaders do not interact with Unity lights like special effects and post-processed effects.

Shader programs are written in HLSL language, by embedding snippets in the shader text, inside the Pass command. They usually look like this:

  Pass {
      // ... the usual pass state setup ...
      
      CGPROGRAM
      // compilation directives for this snippet, e.g.:
      #pragma vertex vert
      #pragma fragment frag
      
      // the Cg/HLSL code itself
      
      ENDCG
      // ... the rest of pass setup ...
  }

HLSL snippets

HLSL program snippets are written between CGPROGRAM and ENDCG keywords, or alternatively between HLSLPROGRAM and ENDHLSL. The latter form does not automatically include HLSLSupport and UnityShaderVariables built-in header files.

At the start of the snippet, compilation directives can be given as #pragma statements. The following table outlines directives that indicate which shader functions to compile:

Other compilation directives:

Each snippet must contain at least a vertex program and a fragment program, so #pragma vertex and #pragma fragment directives are required.

The following compilation directives don’t do anything and can be safely removed:

• #pragma glsl
• #pragma glsl_no_auto_normalization
• #pragma profileoption
• #pragma fragmentoption.

Unity only supports #pragma directives in the shader files, and not in the includes.

Rendering platforms

Unity supports several renderingThe process of drawing graphics to the screen (or to a render texture). By default, the main camera in Unity renders its view to the screen. More info
See in Glossary APIs, like Direct3D 11 and OpenGL, and by default Unity compiles all shader programs into all supported renderers. You can indicate which renderers to compile by using #pragma only_renderers or #pragma exclude_renderers directives. This is useful in cases when you use some shader language features that you aren’t possible on some platforms. Supported renderer names are:

In the example below, this line would only compile a shader into D3D11 mode:

#pragma only_renderers d3d11

See Also

• Accessing Material Properties.
• Writing Multiple Shader Program Variants.
• Shader Compilation Targets.
• Shading Language Details.
• Shader Preprocessor Macros.
• Platform Specific Rendering Differences.

• 2019–05–17 Page amended
• Shader #pragma directives added in Unity 2018.1