Custom Textures

`texture.<stage>.<bufferName> = <path>`

This directive allows a custom texture to be bound to an existing sampler (such as a colortex sampler). This allows the shader to access external textures or specific textures from the resource pack.

Textures can be loaded from the shader pack files by replacing <path> with the file path to the texture relative to the shaders folder. For example texture.composite.colortex5 = textures/perlin.png would load perlin.png from the shaders/textures folder. Iris supports only .png image format, whereas Optifine supports .png and .jpg formats.

Textures can also be loaded from the resource pack by replacing <path> with minecraft: followed by the path in the resourcepack (or vanilla files) of the texture. For example, texture.deferred.colortex7 = minecraft:textures/block/dirt.png will load the dirt texture from the resource pack or vanilla assets.

Finally, dynamic textures can be loaded, such as the lightmap and texture atlases. For example, the lightmap can be loaded with texture.prepare.colortex2 = minecraft:dynamic/lightmap_1, and the texture atlas can be loaded with texture.composite.colortex9 = minecraft:textures/atlas/blocks.png.

For any resource pack or atlas texture, the normal or specular versions of the textuers (if they exist) can be loaded by appending the _n or _s suffix respectively. For example, texture.deferred.colortex2 = minecraft:textures/atlas/blocks_s.png loads the specular block atlas.

Replace <stage> with the stage of programs which the texture will be bound in. During that stage, the colortex sampler specified with <bufferName> will sample the custom texture rather than the colortex buffer. The following options are available for <stage>:

name	description
`setup`	`setup` programs, exclusive to Iris
`begin`	`begin` programs, exclusive to Iris
`shadowcomp`	`shadowcomp` programs
`prepare`	`prepare` programs
`gbuffers`	`gbuffers` and `shadow` programs
`deferred`	`deferred` programs
`composite`	`composite` and `final` programs

Raw Textures

`texture.<stage>.<bufferName> = <path> <type> <internalFormat> <dimensions> <pixelFormat> <pixelType>`

Raw textures (i.e. unencoded binary files) can also be loaded using the above syntax.

<type> can be one of the following: TEXTURE_1D, TEXTURE_2D, TEXTURE_3D, or TEXTURE_RECTANGLE.
Replace <internalFormat> with the texture format.
Replace <dimensions> with the fixed size dimensions of the texture (the number of components depends on the type).
Replace <pixelFormat> with the pixel format described in the “Pixel Formats” section of the texture format section.
Replace <pixelType> with the pixel type described in the “Pixel Types” section of the texture format section.

Iris Enhanced Custom Textures

`customTexture.<name> = <path>`

`customTexture.<name> = <path> <type> <internalFormat> <dimensions> <pixelFormat> <pixelType>`

Iris adds support for the customTexture directive, which allows the shader dev to use a different sampler instead of overriding an existing sampler. This allows creation of a sampler of (mostly) any name, which replaces <name> in the directive and is used in the shader code. Otherwise the syntax of the enhanced custom textures are identical to standard custom textures.