Sample Texture 2D node

The Sample Texture 2D node samples a Texture 2D asset and returns a Vector 4 color value. You can specify the UV coordinates for a texture sample and use a Sampler State node to define a specific Sampler State.

A Sample Texture 2D node can also sample a normal map. For more information, see the Controls section, or Normal map (Bump mapping) in the Unity User manual.

Note

If you experience texture sampling errors for this node in a graph with Custom Function Nodes or Sub Graphs, upgrade to Shader Graph version 10.3 or later.

An image that displays the Graph window with a Sample Texture 2D node.

The Sample Texture 2D node is under the Input > Texture category in the Create Node menu.

Compatibility

The Sample Texture 2D node is supported on the following render pipelines:

Built-In Render Pipeline	Universal Render Pipeline (URP)	High Definition Render Pipeline (HDRP)
Yes	Yes	Yes

With its default settings, this node can only connect to a Block node in the Fragment Context of a Shader Graph. To sample a Texture for the Vertex Context of a Shader Graph, set the Mip Sampling Mode to LOD.

Inputs

The Sample Texture 2D node has the following input ports:

[!include[nodes-sample-uv-table](./snippets/sample-nodes/nodes-sample-uv-table.md)] [!include[nodes-sample-ss-table](./snippets/sample-nodes/nodes-sample-ss-table.md)] [!include[nodes-sample-lod-table](./snippets/sample-nodes/nodes-sample-lod-table.md)] [!include[nodes-sample-mip-bias-table](./snippets/sample-nodes/nodes-sample-mip-bias-table.md)] [!include[nodes-sample-ddx-table](./snippets/sample-nodes/nodes-sample-ddx-table.md)] [!include[nodes-sample-ddy-table](./snippets/sample-nodes/nodes-sample-ddy-table.md)]

Name	Type	Binding	Description
Texture	Texture 2D	None	The Texture 2D asset to sample.

Controls

The Sample Texture 2D node has the following controls:

Name	Type	Description
Type	Dropdown	Select whether the texture is a Texture asset or a normal map.
		Default	The texture is a Texture asset.
		Normal	The texture is a normal map.
Space	Dropdown	When the node's Type is Normal to use a texture as a normal map, choose the Space for the normal map.
		Tangent	Use a Tangent normal map whenever the mesh for a geometry needs to deform or change, such as when animating a character. With Tangent Space, the normal map's normals are relative to the existing vertex normals of any geometry rendered with your Shader Graph. Your Shader Graph only adjusts the vertex normals and not override them.
		Object	Use an Object normal map whenever the mesh for a geometry is static and doesn't deform. With Object Space, the normal map's normals are explicit and override the normals of any geometry rendered with your Shader Graph. Because a static mesh's normals never change, an Object normal map also maintains consistent lighting across different levels of detail (LODs). For more information about normal maps, see Normal map (Bump mapping) in the User manual.

Additional node settings

The Sample Texture 2D node has some additional settings that you can access from the Graph Inspector:

Name	Type	Description
Use Global Mip Bias	Toggle	Enable Use Global Mip Bias to use the render pipeline's Global Mip Bias. This bias adjusts the percentage of texture information taken from a specific mip when sampling. For more information on mip bias, see Mipmaps introduction in the Unity User Manual.
		Enabled	Shader Graph uses the render pipeline's Global Mip Bias to adjust the texture information taken when sampling.
		Disabled	Shader Graph doesn't use the render pipeline's Global Mip Bias to adjust texture information when sampling.
Mip Sampling Mode	Dropdown	Choose the sampling mode to use to calculate the mip level of the texture.
		Standard	The render pipeline calculates and automatically selects the mip for the texture.
		LOD	The render pipeline lets you set an explicit mip for the texture on the node. The texture will always use this mip, regardless of the DDX or DDY calculations between pixels. Set the Mip Sampling Mode to LOD to connect the node to a Block node in the Vertex Context. For more information on Block nodes and Contexts, see Master Stack.
		Gradient	The render pipeline lets you set the DDX and DDY values to use for its mip calculation, instead of using the values calculated from the texture's UV coordinates. For more information on DDX and DDY values, see Mipmaps introduction in the User Manual.
		Bias	The render pipeline lets you set a bias to adjust the calculated mip for a texture up or down. Negative values bias the mip to a higher resolution. Positive values bias the mip to a lower resolution. The render pipeline can add this value to the value of the Global Mip Bias, or use this value instead of its Global Mip Bias. For more information on mip bias, see Mipmaps introduction in the User Manual.

Outputs

The Sample Texture 2D node has the following output ports:

Name	Type	Description
RGBA	Vector 4	The full RGBA Vector 4 color value of the texture sample.
R	Float	The Red channel or X component of the texture sample.
G	Float	The Green channel or Y component of the texture sample.
B	Float	The Blue channel or Z component of the texture sample.
A	Float	The Alpha channel or W component of the texture sample.

Example graph usage

In the following example, the Sample Texture 2D node uses a Subgraph node that generates UV coordinates in latitude and longitude format. These latitude and longitude UV coordinates help render the latlong_test 2D Texture asset, which was created and formatted with a latitude and longitude projection. The generated latitude and longitude UVs accurately map the 2D Texture asset onto a spherical geometry.

If the Sample Texture 2D node uses the Standard Mip Sampling Mode, the Texture displays with a seam along the side of the sphere where the left and right sides of the texture meet. The latitude and longitude UV coordinates for sampling the texture jump from 0 to 1 at the seam on the model, which causes a problem with the mip level calculation in the sample. The error in the mip level calculation causes the seam. The texture requires a different mip sampling mode to remove the seam.

An image of the Graph window, that displays a UV Lat Long Subgraph node connected to the UV input port on a Sample Texture 2D node. The Sample Texture 2D provides its RGBA output to the Base Color Block node in the Master Stack. The Main Preview of the sampled Texture has a noticeable seam along the middle of the sphere.

When the Mip Sampling Mode is set to Gradient, the Sample Texture 2D node can use the standard set of UVs for the model in the mip level calculation, instead of the latitude and longitude UVs needed for sampling the texture. The new UV coordinates passed into the DDX and DDY input ports result in a continuous mip level, and remove the seam.

An image of the Graph window, that displays the same Sample Texture 2D node as the previous image. This time, the Mip Sampling Mode in the Graph Inspector has been set to Gradient. The new DDX and DDY input ports on the Sample Texture 2D node receive input from a DDX and DDY node, with input from a UV node. The seam on the Main Preview of the Texture has disappeared.

Generated code example

The following code represents this node in Unity's shader code, based on the selected Type on the Sample Texture 2D node:

Default

float4 _SampleTexture2D_RGBA = SAMPLE_TEXTURE2D(Texture, Sampler, UV);
float _SampleTexture2D_R = _SampleTexture2D_RGBA.r;
float _SampleTexture2D_G = _SampleTexture2D_RGBA.g;
float _SampleTexture2D_B = _SampleTexture2D_RGBA.b;
float _SampleTexture2D_A = _SampleTexture2D_RGBA.a;

Normal

float4 _SampleTexture2D_RGBA = SAMPLE_TEXTURE2D(Texture, Sampler, UV);
_SampleTexture2D_RGBA.rgb = UnpackNormalmapRGorAG(_SampleTexture2D_RGBA);
float _SampleTexture2D_R = _SampleTexture2D_RGBA.r;
float _SampleTexture2D_G = _SampleTexture2D_RGBA.g;
float _SampleTexture2D_B = _SampleTexture2D_RGBA.b;
float _SampleTexture2D_A = _SampleTexture2D_RGBA.a;

The following nodes are related or similar to the Sample Texture 2D node: