TSL Structs: Ability to pass structs as uniforms

[TheBlek]

Description

When passing multiple related uniforms around its handy to group them in structs:

const environmentInfoStruct = struct({
  rotation: 'mat3',
  intensity: 'float',
  blur: 'float',
}, 'EnvironmentInfo' );

fn sampleEnvironment(
	envMap: texture_2d<f32>,
	envMapSampler: sampler,
	env: EnvironmentInfo,
	direction: vec3f,
	uv: vec2f,
) -> vec3f {

///

}

Yet it does not seem possible to pass uniforms as a single struct. Maybe there is an example I missed?

uniform node docs do not mention structs and there does not seem to be any special node for uniform structs.

three.js/src/nodes/core/UniformNode.js

Line 223 in 3ca54b0

* @param {any|string} value - The value of this uniform or your type. Usually a JS primitive or three.js object (vector, matrix, color, texture).

uniform( environmentInfoStruct( { /* values */ } ) )
uniform( { /* values */ } )
environmentInfoStruct( { /* values */ } )

All of the above does not seem to work.

Solution

Add support for passing structs as uniforms. uniform( /* struct value */ ) seems to be the most intuitive.

And it would be perfect if structs could be updated from a js object to avoid assigning every field. I'm not sure how it should be done syntactically. Along the lines of:

const envInfo = environmentInfoStruct( { /* values */ } );
envInfo.assign( { /* new values */ } );

Alternatives

Pass each primitive in the struct as a separate uniform and group them at the start of the function:

envMapRotation: uniform( new Matrix3() ),
envMapIntensity: uniform( 1 ),
envMapBlur: uniform( 0 ),

---

let envInfo = EnvironmentInfo(
	envMapRotation,
	envMapIntensity,
	envMapBlur,
);

Additional context

No response