# Built-in shader variables reference > Reference for the global variables Unity provides for your custom shaders, such as transformation matrices and light parameters. Unity's built-in include files contain global variables for your shaders: things like current object's transformation matrices, light parameters, current time and so on. You use them in [shader programs](/engine/6000.6/manual/materials-and-shaders/shaders/writing-custom/shader-writing/sl/writing-shader-writing-shader-programs-hlsl.md) like any other variable, but if you include the relevant include file, you don't have to declare them. For more information on include files, see [Built-in include files](/engine/6000.6/manual/materials-and-shaders/shaders/writing-shaders-birp/use-built-in-shader-methods-birp/sl-builtin-includes.md). ## Inline sampler suffixes Add the following suffixes when you declare an inline `SamplerState` sampler in HLSL code, to manually set texture filtering and wrapping modes. Separate multiple words with an underscore (`_`). For example, to set a sampler to use linear filtering and repeat wrapping mode, name it `sampler_linear_repeat`. > **Note:** > > These sampler suffixes only work if you target the DX11, DX12, Metal or Vulkan graphics API. You must include a single filtering mode and a single texture wrapping mode. The other suffixes are optional. | **Suffix** | **Description** | | --------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `point` | Enables nearest texture filtering. | | `linear` | Enables bilinear texture filtering. | | `trilinear` | Enables trilinear texture filtering. | | `clamp` | Sets the texture wrapping mode to clamp. | | `repeat` | Sets the texture wrapping mode to repeat. | | `mirror` | Sets the texture wrapping mode to mirror. | | `mirroronce` | Sets the texture wrapping mode to mirror once. If you target a mobile platform that doesn't support `mirroronce`, Unity falls back to `mirror`. | | `compare` | Sets the sampler to compare depth values. For more information refer to [SampleCmp](https://learn.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-to-samplecmp) and [SampleCmpLevelZero](https://learn.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-to-samplecmplevelzero) in the Microsoft HLSL documentation. | | `aniso2`, `aniso4`, `aniso8`, `aniso16` | Enables anisotropic filtering with 2x, 4x, 8x, or 16x sampling. Depending on the graphics API and platform you target, Unity might clamp the filtering to a lower value, or disable anisotropic filtering completely. | Add `U`, `V` or `W` to a wrap mode to set the wrapping mode for that axis only. For example, `sampler_clampu_point` sets the U axis to clamp mode, and leaves the V and W axes at their default wrapping mode. For more information, refer to: * [`Texture.wrapMode`](/engine/6000.6/script-reference/unityengine/texture/wrapmode.md) * [`Texture.anisoLevel`](/engine/6000.6/script-reference/unityengine/texture/anisolevel.md) * [`Texture.filterMode`](/engine/6000.6/script-reference/unityengine/texture/filtermode.md) ## Transformations All these matrices are `float4x4` type, and are column major. > **Note:** > > If you use the Universal Render Pipeline (URP), you can also use variables from the `Core.hlsl` library file. For more information, refer to [Transform positions in a custom URP shader](/engine/6000.6/manual/materials-and-shaders/shaders/writing-custom-shaders-urp/use-built-in-shader-methods/transformations.md). | **Name** | **Value** | | --------------------- | ------------------------------------------- | | UNITY\_MATRIX\_MVP | Current model \* view \* projection matrix. | | UNITY\_MATRIX\_MV | Current model \* view matrix. | | UNITY\_MATRIX\_V | Current view matrix. | | UNITY\_MATRIX\_P | Current projection matrix. | | UNITY\_MATRIX\_VP | Current view \* projection matrix. | | UNITY\_MATRIX\_T\_MV | Transpose of model \* view matrix. | | UNITY\_MATRIX\_IT\_MV | Inverse transpose of model \* view matrix. | | unity\_ObjectToWorld | Current model matrix. | | unity\_WorldToObject | Inverse of current model matrix. | ## Camera and screen These variables will correspond to the [Camera](/engine/6000.6/manual/cameras/birp/class-camera.md) that is rendering. For example during shadowmap rendering, they will still refer to the Camera component values, and not the "virtual camera" that is used for the shadowmap projection. > **Note:** > > If you use the Universal Render Pipeline (URP), you can also use variables from the `Core.hlsl` library file. For more information, refer to [Use the camera in a custom URP shader](/engine/6000.6/manual/materials-and-shaders/shaders/writing-custom-shaders-urp/use-built-in-shader-methods/camera.md). | **Name** | **Type** | **Value** | | -------------------------------- | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | \_WorldSpaceCameraPos | float3 | World space position of the camera. | | \_ProjectionParams | float4 | `x` is 1.0 (or -1.0 if currently rendering with a [flipped projection matrix](/engine/6000.6/manual/materials-and-shaders/shaders/writing-custom/shader-writing/sl/writing-shader-writing-shader-programs-hlsl/sl-platform-differences.md)), `y` is the camera's near plane, `z` is the camera's far plane and `w` is 1/FarPlane. | | \_ScreenParams | float4 | `x` is the width of the camera's target texture in pixels, `y` is the height of the camera's target texture in pixels, `z` is 1.0 + 1.0/width and `w` is 1.0 + 1.0/height. | | \_ZBufferParams | float4 | Used to linearize Z buffer values.`x`: `1 - far/near`, or `-1 + far/near` if `UNITY_REVERSED_Z` is set to 1.For more information about `UNITY_REVERSED_Z`, refer to [Branch based on platform features](/engine/6000.6/manual/materials-and-shaders/shaders/writing-custom/shader-writing/shader-branching-built-in-macros/platform.md).`y`: `far/near`, or `1` if `UNITY_REVERSED_Z` is set to 1.For more information about `UNITY_REVERSED_Z`, refer to [Branch based on platform features](/engine/6000.6/manual/materials-and-shaders/shaders/writing-custom/shader-writing/shader-branching-built-in-macros/platform.md).`z`: `x / far``w`: `y / far` | | unity\_OrthoParams | float4 | The following parameters:`x`: half the width of the camera view in world space`y`: half the height of the camera view in world space`z`: unused`w`: 1.0 if the camera is orthographic, or 0.0 if the camera is perspective | | unity\_CameraProjection | float4x4 | Camera's projection matrix. | | unity\_CameraInvProjection | float4x4 | Inverse of camera's projection matrix. | | unity\_CameraWorldClipPlanes\[6] | float4 | Camera frustum plane world space equations, in this order: left, right, bottom, top, near, far. | ## Time Time is measured in seconds, and is scaled by the Time multiplier in your Project's [Time settings](/engine/6000.6/manual/unity-editor/editor-settings-reference/comp-manager-group/class-time-manager.md). There is no built-in variable that provides access to unscaled time. Time matches `Time.time`, which is the time since the application started. If you use the Built-In Render Pipeline, time matches `Time.timeSinceLevelLoad` instead. | **Name** | **Type** | **Value** | | ---------------- | -------- | ----------------------------------------------------------- | | \_Time | float4 | `(t/20, t, t\*2, t\*3)`. Use for animations inside shaders. | | \_SinTime | float4 | Sine of time: (t/8, t/4, t/2, t). | | \_CosTime | float4 | Cosine of time: (t/8, t/4, t/2, t). | | unity\_DeltaTime | float4 | Delta time: (dt, 1/dt, smoothDt, 1/smoothDt). | ## Lightmaps | **Name** | **Type** | **Value** | | ----------------- | ---------- | --------------------------------------------------------------------------------------------- | | unity\_Lightmap | Texture2D | Contains lightmap information. | | unity\_LightmapST | float4\[8] | Scales and translates the UV information to the correct range to sample the lightmap texture. | ## Fog and Ambient | **Name** | **Type** | **Value** | | -------------------------- | -------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | unity\_AmbientSky | fixed4 | Sky ambient lighting color in gradient ambient lighting case. | | unity\_AmbientEquator | fixed4 | Equator ambient lighting color in gradient ambient lighting case. | | unity\_AmbientGround | fixed4 | Ground ambient lighting color in gradient ambient lighting case. | | unity\_IndirectSpecColor | fixed4 | If you use a [skybox](/engine/6000.6/manual/creating-environments/sky/skyboxes-using.md), this is the average color of the skybox, which Unity calculates using the `DC` component of the [spherical harmonics data](/engine/6000.6/manual/lighting-overview/direct-and-indirect-lighting/lightmap-data/light-probes-technical-information.md) in the [ambient probe](/engine/6000.6/script-reference/unityengine/rendersettings/ambientprobe.md). Otherwise this is black. | | UNITY\_LIGHTMODEL\_AMBIENT | fixed4 | Ambient lighting color (sky color in gradient ambient case). Legacy variable. | | unity\_FogColor | fixed4 | Fog color. | | unity\_FogParams | float4 | Parameters for fog calculation: (density / sqrt(ln(2)), density / ln(2), -1/(end-start), end/(end-start)). *x* is useful for Exp2 fog mode, *y* for Exp mode, *z* and *w* for Linear mode. | ## Various | **Name** | **Type** | **Value** | | ------------------ | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | unity\_LODFade | float4 | Level-of-detail fade when using [LODGroup](/engine/6000.6/manual/analysis/graphics-performance-profiling/lod/lod-group/class-lodgroup.md). *x* is fade (0..1), *y* is fade quantized to 16 levels, *z* and *w* unused. | | \_TextureSampleAdd | float4 | Set automatically by Unity **for UI only** based on whether the texture being used is in Alpha8 format (the value is set to (1,1,1,0)) or not (the value is set to (0,0,0,0)). |