Targeting graphics APIs and platforms in HLSL

Some #pragma directives take parameters that allow you to target specific graphics APIs and platforms. This page contains information on using those directives, and provides a list of valid parameter values.

Including or excluding graphics APIs

By default, Unity compiles all shaderA program that runs on the GPU. More info
See in Glossary programs for each graphics API in the list for the current build target. Sometimes, you might want to compile certain shader programs only for certain graphics APIs; for example, if you use features that are not supported on all platforms.

To compile a shader program only for given APIs, use the #pragma only_renderers directive. You can pass multiple values, space delimited.

This example demonstrates how to compile shaders only for Metal and Vulkan:

#pragma only_renderers metal vulkan

To exclude shader code from compilation by given compilers, use the #pragma exclude_renderers directive. You can pass multiple values, space delimited.

This example demonstrates how to exclude a shader from compilation for Metal and Vulkan:

#pragma exclude_renderers metal vulkan

Generating shader variants for graphics tiers for a given graphics API

In the 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, Unity automatically generates shader variantsA verion of a shader program that Unity generates according to a specific combination of shader keywords and their status. A Shader object can contain multiple shader variants. More info
See in Glossary that correspond to graphics tiers under certain conditions. You can also force Unity to generate these variants, if required.

To do this, use the #pragma hardware_tier_variants preprocessor directive and specify the graphics APIs for which you want to generate tier shader variants.

For example, this instructs Unity to compile tier shader variants for Metal:

#pragma hardware_tier_variants metal

List of valid parameter values

Supported values are: