testing WebGPURenderer and TSL (do not merge)

[vincentfretin]

Description:

For those that want to play with WebGPURenderer and TSL

Changes proposed:

• Rename a-node isNode to isAframeNode, this was the cause of infinite loop with build function on WebGPURenderer when building a shader
• Import from three/webgpu instead of three
• Set dummy renderer.xr.setPoseTarget for now

[dmarcos]

We should def understand what's going on here

[vincentfretin]

The infinite loop was here https://github.com/mrdoob/three.js/blob/a5734130516db50c1de2cdfe27f477a33ecd1c87/src/nodes/core/Node.js#L640-L648
I don't know much about the new node system to say what that code is doing.

[vincentfretin]

As I said in #5363 (comment) my guess is that in aframe we set a reference to the entity with el on a three object.

Doing a search I get the following places:

$ ag "\.el = " src/
src/core/system.js
31:  this.el = sceneEl;

src/core/component.js
66:  this.el = el;

src/core/a-entity.js
36:    this.object3D.el = this;
111:    this.object3D.el = null;
140:    obj.el = this;
143:        child.el = self;

src/components/material.js
112:    shaderInstance.el = this.el;

src/components/light.js
205:      this.light.el = el;

src/components/text.js
437:  shaderObject.el = el;

My guess is that the one set on shaderInstance.el is the culprit and end up in the shader/material being build, but not sure how, I'm not familiar with the new webgpu code path.

[dmarcos]

Cool. I would postpone this to 1.8.0. I will be cool to have a WebGPU path.