Sample a 2D texture array in a shader

To sample a texture array in a custom shaderA program that runs on the GPU. More info
See in Glossary, follow these steps:

To create a texture array material property, add a 2DArray material property declaration. For example:
```
Properties
{
    _MainTex ("Texture array", 2DArray) = "" {}
}
```
To set the texture array as a shader input, add a UNITY_DECLARE_TEX2DARRAY macro. For example:
```
UNITY_DECLARE_TEX2DARRAY(_MainTex);
```
To sample a slice of the texture array, use the UNITY_SAMPLE_TEX2DARRAY method. For example to sample slice 1 of the texture array:
```
half4 frag (v2f i) : SV_Target {
    float4 color = UNITY_SAMPLE_TEX2DARRAY(_MainTex, float3(0, 0, 1));
}
```
To sample a mipmap level of a slice of the texture array, use the UNITY_SAMPLE_TEX2DARRAY_LOD method. For example to sample slice 1 of the texture array at mipmap level 0:
```
half4 frag (v2f i) : SV_Target {
    float4 color = UNITY_SAMPLE_TEX2DARRAY_LOD(_MainTex, float3(0, 0, 1), 0);
}
```

Target platforms that support 2D texture arrays

To target custom shaders only at platforms that support texture arrays, use either of the following:

#pragma target 3.5 to target shader model 3.5 and higher.
#pragma require 2darray to target GPUs that support texture arrays.

Example

The following shader example samples a texture array using object space vertex positions as coordinates, and runs only on GPUs that support texture arrays.

Shader "Example/Sample2DArrayTexture"
{
    Properties
    {
        // Create material properties for the 2D texture array and the slices to sample 
        _MyArr ("Tex", 2DArray) = "" {}
        _SliceRange ("Slices", Range(0,16)) = 6

        _UVScale ("UVScale", Float) = 1.0
    }
    SubShader
    {
        Pass
        {
            CGPROGRAM

            #pragma vertex vert
            #pragma fragment frag

            // Compile the shader only on platforms that support texture arrays
            #pragma require 2darray

            #include "UnityCG.cginc"

            struct v2f
            {
                float3 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };

            float _SliceRange;
            float _UVScale;

            v2f vert (float4 vertex : POSITION)
            {
                v2f o;
                o.vertex = mul(UNITY_MATRIX_MVP, vertex);
                o.uv.xy = (vertex.xy + 0.5) * _UVScale;

                // Set the z coordinate to the slice indices
                o.uv.z = (vertex.z + 0.5) * _SliceRange;

                return o;
            }
            
            // Set the texture array as a shader input
            UNITY_DECLARE_TEX2DARRAY(_MyArr);

            half4 frag (v2f i) : SV_Target
            {
                // Sample the texture array
                return UNITY_SAMPLE_TEX2DARRAY(_MyArr, i.uv);
            }

            ENDCG
        }
    }
}

Additional resources

Render to a 2D texture array

Cubemaps

Unity Manual

Sample a 2D texture array in a shader

Target platforms that support 2D texture arrays

Example

Additional resources