TSL: toVar inside IF triggers incorrect warning "Declaration name '...' of 'vec3' already in use. Renamed to '...'"

[plotta-boop-beep123]

Description

The code below triggers an "already in use" warning in the console, even though the variable is defined only once (and renaming it doesn't change the behavior). If THREE.TSL.If(THREE.TSL.bool(true), () => { is removed (making the code unconditional), the warning disappears. The same happens if "toVar()" is removed.

I get the following output in the console after running the code (for some reason, there are 2 logs from the debug node):

THREE.// #--- TSL debug - vertex shader ---#

if ( true ) {

	POSITION_origin = POSITION_v_positionWorld;
	positionLocal = ( POSITION_v_positionWorld - POSITION_origin );

/* ... */ positionLocal /* ... */
// #---------------------------------#
_display:62:35

THREE.TSL: Declaration name 'origin' of 'vec3' already in use. Renamed to 'origin_1'. Stack trace not available. Enable "THREE.Node.captureStackTrace" to capture stack traces. _display:72:36

THREE.// #--- TSL debug - vertex shader ---#
modelViewMatrix = ( render.cameraViewMatrix * object.nodeUniform0 );

if ( true ) {

	positionLocal = ( v_positionWorld - origin );

/* ... */ positionLocal /* ... */
// #---------------------------------#

Reproduction steps

Code

I am not entirely sure if it's a bug or I don't know how to use TSL properly. Minimal example:

import * as THREE from 'https://unpkg.com/three@0.184.0/build/three.webgpu.js';

const renderer = new THREE.WebGPURenderer();
const camera = new THREE.PerspectiveCamera(55, 1, 0.01, 100);
const scene = new THREE.Scene();
 
const geometry = new THREE.BufferGeometry();
geometry.setAttribute('position', new THREE.Float32BufferAttribute([0,1,2, 3,4,5, 6,7,8, 9,10,11, 12,13,14], 3));

scene.add(new THREE.Points(geometry, new THREE.PointsNodeMaterial({

  positionNode: THREE.TSL.Fn(() => {
    const output = THREE.TSL.positionLocal;
 
    THREE.TSL.If(THREE.TSL.bool(true), () => { 
      const origin = THREE.TSL.positionWorld.toVar('origin'); // <===============================
      output.xyz.assign(THREE.TSL.positionWorld.sub(origin)).debug();
    });

    return output;
  })() 

})));

renderer.init().then(() => renderer.render(scene, camera));

Live example

• jsfiddle

Screenshots

No response

Version

r184

Device

Desktop

Browser

Firefox

OS

Windows

[Mugen87]

I can reproduce the issue. And the warning is indeed correct. positionNode is being built twice under two different sub-build scopes, and .toVar('origin') gets a declaration registered in each scope.

I think this is specific to PointsNodeMaterial though since the first build happens in NodeMaterial.setupPosition(), the other one in PointsNodeMaterial.setupPositionView(). The latter one references the raw positionNode again, not inside the 'POSITION' sub-build.

Edit: SpriteNodeMaterial seems to require a similar fix since it also overwrites setupPositionView() and evaluates positionNode.

Probably best if @sunag suggest a spot for the fix.

[sunag]

I've detected a problem, which must also be affecting performance. I hope to resolve it in the next few days.