Version: 2021.3
pragma directives in HLSL
Targeting graphics APIs and platforms in HLSL

Targeting shader models and GPU features in HLSL

You can use #pragma directives to indicate that a shaderA program that runs on the GPU. More info
See in Glossary
requires certain GPU features. At runtime, Unity uses this information to determine whether a shader program is compatible with the current hardware.

You can specify individual GPU features with the #pragma require directive, or specify a shader model with the #pragma target directive. A shader model is a shorthand for a group of GPU features; internally, it is the same as a #pragma require directive with the same list of features.

It is important to correctly describe the GPU features that your shader requires. If your shader uses features that are not included in the list of requirements, this can result in either compile time errors, or in devices failing to support shaders at runtime.

Default behavior

By default, Unity compiles shaders with #pragma require derivatives, which corresponds to #pragma target 2.5.

Special requirements for shader stages

If your shader defines certain shader stages, Unity automatically adds items to the list of requirements.

  • If a shader defines a geometry stage (with #pragma geometry), Unity automatically adds geometry to the list of requirements.
  • If a shader defines a tessellation stage (with #pragma hull or #pragma domain), Unity automatically adds tessellation to the list of requirements.

If the list of requirements (or the equivalent target value) does not already include these values, Unity displays a warning message when it compiles the shader, to indicate that it has added these requirements. To avoid seeing this warning message, explicitly add the requirements or use an appropriate target value in your code.

Specifying GPU features or a shader model

To specify required features, use the #pragma require directive, followed by a list of space-delimited values. For example:

#pragma require integers mrt8

You can also use the #pragma require directive followed by a colon and a list of space-delimited shader keywords. This means that the requirement applies only to variants that are used when any of the given keywords are enabled.

For example:

#pragma require integers mrt8 : EXAMPLE_KEYWORD OTHER_EXAMPLE_KEYWORD

You can use multiple #pragma require lines. In this example, the shader requires integers in all cases, and mrt8 if EXAMPLE_KEYWORD is enabled.

#pragma require integers
#pragma require integers mrt8 : EXAMPLE_KEYWORD

To specify a shader model, use #pragma target directive. For example:

#pragma target 4.0

You can also use the #pragma target directive followed by a list of space-delimited shader keywords. This means that the requirement applies only to variants that are used when any of the given keywords are enabled.

For example:

#pragma target 4.0 EXAMPLE_KEYWORD OTHER_EXAMPLE_KEYWORD

Note: The syntax for specifying keywords for #pragma require and #pragma target is slightly different. When you specify keywords for #pragma require, you use a colon. When you specify keywords for #pragma target, you do not use a colon.

List of ‘#pragma target’ values

Here is the list of shader models that Unity uses, and the combination of #pragma require values that each corresponds to.

Note: Unity’s shader models are similar to DirectX shader models and OpenGL version requirements, but they do not correspond exactly. Read the descriptions carefully to ensure that you understand the differences.

Value Description Support Equivalent #pragma require values
2.0 Equivalent to DirectX shader model 2.0.

Limited amount of arithmetic and texture instructions; 8 interpolators; no vertex texture sampling; no derivatives in fragment shaders; no explicit LOD texture sampling.
Works on all platforms supported by Unity. N/A
2.5 Almost the same as 3.0, but with only 8 interpolators, and no explicit LOD texture sampling. DirectX 11 feature level 9+
OpenGL 3.2+
OpenGL ES 2.0
Vulkan
Metal
derivatives
3.0 Equivalent to DirectX shader model 3.0.

.
DirectX 11 feature level 10 +
OpenGL 3.2+
OpenGL ES 3.0+
Vulkan
Metal

Might work on some OpenGL ES 2.0 devices, depending on driver extensions and features.
Everything in 2.5, plus:
interpolators10 samplelod fragcoord
3.5 Equivalent to OpenGL ES 3.0.

DirectX 11 feature level 10+
OpenGL 3.2+
OpenGL ES 3+
Vulkan
Metal
Everything in 3.0, plus:
interpolators15 mrt4 integers 2darray instancing
4.0 Equivalent to DirectX shader model 4.0, but without the requirement to support 8 MRTs. DirectX 11 feature level 10+
OpenGL 3.2+
OpenGL ES 3.1+AEP
Vulkan
Metal (if no geometry stage is defined)
Everything in 3.5, plus:
geometry
4.5 Equivalent to OpenGL ES 3.1. DirectX 11 feature level 11+
OpenGL 4.3+
OpenGL ES 3.1
Vulkan
Metal
Everything in 3.5, plus:
compute randomwrite msaatex
4.6 Equivalent to OpenGL 4.1.

This is the highest OpenGL level supported on a Mac.
DirectX 11 feature level 11+
OpenGL 4.1+
OpenGL ES 3.1+AEP
Vulkan
Metal (if no geometry stage is defined, and no hull or domain stage is defined)
Everything in 4.0, plus:
cubearray tesshw tessellation msaatex
5.0 Equivalent to DirectX shader model 5.0, but without the requirement to support 32 interpolators or cubemap arrays. DirectX 11 feature level 11+
OpenGL 4.3+
OpenGL ES 3.1+AEP
Vulkan
Metal (if no geometry stage is defined, and no hull or domain stage is defined)
Everything in 4.0, plus:
compute randomwrite msaatex tesshw tessellation

For information on shader model support for console platforms, see the platform-specific documentation.

Notes:

  • In the DirectX definitions, shader model 4.0 includes mrt8, and shader model 5.0 includes interpolators32 and cubearray. Unity does not include these, for broader compatibility. To require these features, use an explicit #pragma require directive.
  • If you use a target that requires geometry but your shader does not define a geometry stage, Unity removes geometry from the list of requirements at compile time.
  • If you use a target that requires tessellation but your shader does not define a hull or domain stage, Unity removes tessellation from the list of requirements at compile time.

List of ‘#pragma require’ values

Here are all the valid values for the #pragma require directive.

Value Description
interpolators10 At least 10 vertex-to-fragment interpolators (“varyings”) are available.
interpolators15 At least 15 vertex-to-fragment interpolators (“varyings”) are available.

Note: Internally, this also automatically adds integers to the list of requirements.
interpolators32 At least 32 vertex-to-fragment interpolators (“varyings”) are available.
integers Integers are a supported data type, including bit/shift operations.

Note: Internally, this also automatically adds interpolators15 to the list of requirements.
mrt4 At least 4 render targets are supported.
mrt8 At least 8 render targets are supported.
derivatives PixelThe smallest unit in a computer image. Pixel size depends on your screen resolution. Pixel lighting is calculated at every screen pixel. More info
See in Glossary
shader derivative instructions (ddx/ddy) are supported.
samplelod Explicit texture LODThe Level Of Detail (LOD) technique is an optimization that reduces the number of triangles that Unity has to render for a GameObject when its distance from the Camera increases. More info
See in Glossary
sampling (tex2Dlod / SampleLevel) is supported.
fragcoord Pixel location (XY on screen, ZW depth in clip space) input in pixel shader is supported.
2darray 2D texture arrays are a supported data type.
cubearray CubemapA collection of six square textures that can represent the reflections in an environment or the skybox drawn behind your geometry. The six squares form the faces of an imaginary cube that surrounds an object; each face represents the view along the directions of the world axes (up, down, left, right, forward and back). More info
See in Glossary
arrays are a supported data type.
instancing SV_InstanceID input system value is supported.
geometry Geometry shader stages are supported.
compute Compute shaders, structured buffers, and atomic operations are supported.
randomwrite or uav “Random write” (UAV) textures are supported.
tesshw Hardware tessellation is supported, but not necessarily tessellation (hull/domain) shader stages. For example, Metal supports tessellation, but not hull or domain stages.
tessellation Tessellation (hull/domain) shader stages are supported.
msaatex The ability to access multi-sampled textures (Texture2DMS in HLSL) is supported.
sparsetex Sparse textures with residency info (“Tier2” support in DirectX terms; CheckAccessFullyMapped HLSL function).
framebufferfetch or fbfetch Framebuffer fetch (the ability to read input pixel color in the pixel shader) is supported.
setrtarrayindexfromanyshader Setting the render target array index from any shader stage (not just the geometry shader stage) is supported.
pragma directives in HLSL
Targeting graphics APIs and platforms in HLSL