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Pass information to shader compilers in HLSL

Use the define, pragma, and defineforplatform_compiler directives to pass information to the shader compiler.
読み終わるまでの所要時間 3 分最終更新 11日前
To pass information to the shader compilers in High-Level Shader Language (HLSL), use one of the following directives:
  • The standard HLSL 
    #define
    directive.
  • The standard HLSL 
    #pragma
    directive, to pass standard HLSL or Unity-specific directives.
  • The Unity 
    #define_for_platform_compiler
    directive.

Add a #define directive

Unity supports the standard HLSL 
#define
directive. For more information, see # define directive in the Microsoft HLSL documentation. For example:
Shader "Custom/ExampleShader"{    SubShader    {        Pass        {            HLSLPROGRAM            // Define a symbol called EXAMPLE_SYMBOL            #define EXAMPLE_SYMBOL            // Add your shader code here            ENDHLSL        }    }}

Add a #pragma directive

Use a 
#pragma
directive to do the following:
  • Pass Unity-specific directives, for example to add shader keywords or target specific graphics APIs. For more information, refer to HLSL pragma directives reference.
  • Pass standard HLSL directives. For more information, refer to # pragma directive in the Microsoft HLSL documentation.
Add a 
#pragma
statement anywhere in your 
HLSLPROGRAM
, but usually at the start. For example:
Shader "Custom/ExampleShader"{    SubShader    {        Pass        {            HLSLPROGRAM            // Target shader model 3.0            #pragma target 3.0            // Compile this shader only for Direct3D 11 and OpenGL Core            #pragma only_renderers d3d11 glcore            // Add your shader code here            ENDHLSL        }    }}

Limitations

Unity recognizes 
#pragma
directives only in the following contexts:
  • Unity-specific directives: In 
    .shader
    files, or files you include with the 
    #include_with_pragmas
    directive.
  • Standard HLSL directives: In files you include with the 
    #include
    directive.
Unity ignores 
#pragma
directives outside these contexts.
注
If a shader file uses 
#include
to import a file that contains an 
#include_with_pragmas
directive, Unity ignores the 
#pragma
directives in the file the 
#include_with_pragmas
directive references.
If you put a 
#pragma
directive inside an 
#if
statement, the condition must depend on one of the following:

Add a #define_for_platform_compiler directive

To pass information to the platform-specific shader compiler, for example the FXC compiler if you target a platform that uses DirectX, add a 
#define_for_platform_compiler
directive. For example:
Shader "Custom/ExampleShader"{    SubShader    {        Pass        {            HLSLPROGRAM            // Define a symbol called EXAMPLE_SYMBOL for the platform-specific shader compiler            #define_for_platform_compiler EXAMPLE_SYMBOL            // Add your shader code here            ENDHLSL        }    }}
The directive sends a 
#define
directive to the platform-specific shader compiler. For example, 
#define_for_platform_compiler EXAMPLE_SYMBOL
sends a 
#define EXAMPLE_SYMBOL
directive to the shader compiler.
The Unity preprocessor doesn't use symbols you define with 
#define_for_platform_compiler
. If you use the symbols inside conditional statements in your own shader code, the code won't run.

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