A texture array is a collection of same size/format/flags 2D textures that look like a single object to the GPU, and can be sampled in the shader with a texture element index. They are useful for implementing custom terrain rendering systems or other special effects where you need an efficient way of accessing many textures of the same size and format. Elements of a 2D texture array are also known as slices, or layers.
Texture arrays need to be supported by the underlying graphics API and the GPU. They are available on:
Other platforms do not support texture arrays (OpenGL ES 2.0 or WebGL 1.0). Use SystemInfo.supports2DArrayTextures to determine texture array support at runtime.
You can import texture arrays from source texture files that are divided into cells. These are called flipbook textures. To do this:
For more information, see Texture import settings.
To create a texture array from a C# script, use the Texture2DArray class to initialize the texture and set pixel data, and save the object as an asset file using AssetDatabase.CreateAsset.
Normally, texture arrays are used purely within GPU memory, but you can use Graphics.CopyTexture, Texture2DArray.GetPixels and Texture2DArray.SetPixels to transfer pixels to and from system memory.
Texture array elements may also be used as render targets. Use RenderTexture.dimension to specify in advance whether the render target is to be a 2D texture array. The depthSlice argument to Graphics.SetRenderTarget specifies which mipmap level or cube map face to render to. On platforms that support “layered rendering” (i.e. geometry shaders), you can set the depthSlice argument to –1 to set the whole texture array as a render target. You can also use a geometry shader to render into individual elements.