luma.gl/docs/api-reference/shadertools/shader-modules.md

Core Shader Modules

Uniform Blocks

Shader modules are built around a set of well-defined uniform interface blocks.

Interface Block	Binding (Group)	Description	Usage
project	0 (0)	camera world position, view and projection matrices	Usually static for a view render cycle
lighting	1 (0)	ambient light color, directional light array, point light color array	Usually static for a scene
material	2 (1)	PBR parameters, base color, ...	Uniform buffer can be pre-calculated for each material and swapped in
postprocessing	3	parameters for current post processing effect (often independent of other interfaces)

This helps respect the limited budget for uniform blocks.

Shader Passes

It is possible to package up many typical screen-space post-processing steps as a shader module.

Sometimes a pass needs to be run several times with some internal uniform changed. This can be described by adding the passes field to a shader module.

Defining your own Shader Modules

It is critical that the order and types of declarations of uniforms match those in the shader.