chore: Investigate Vetor3 in three.js

[aleksanderkatan]

The following seems to create vec4f array under the hood:

  const attractorsPositions = uniformArray([
    new THREE.Vector3(-1, 0, 0),
    new THREE.Vector3(1, 0, -0.5),
    new THREE.Vector3(0, 0.5, 1),
  ]);

This makes the following not work as intended:

  const attractorsPositionsAccess = fromTSL(attractorsPositions, {
    type: d.arrayOf(d.vec3f),
  });

[aleksanderkatan]

While for buffers I seem to be able to declare them as vec3f and just use .xyz to avoid problems, it doesn't seem possible with atributes.

const velocityBuffer = instancedArray(count, 'vec3');

const velocityBufferAttributeAccessor = fromTSL(velocityBuffer.toAttribute(), {
  type: d.vec3f,
});

Error while parsing WGSL: :50:9 error: cannot assign 'vec4<f32>' to 'vec3<f32>'
  item_8 = nodeVarying3;
         ^


 - While calling [Device].CreateShaderModule([ShaderModuleDescriptor ""fragment""]).

[aleksanderkatan]

In #1988 we found out that uniformArray seems to always try to align to 16 bytes, even a float gets promoted to vec4