Unable to access geometry array of points in pointcloud a-frame and threeJS - aframe

Question

I have an a-frame entity with a component which is generating a pointcloud made of points in the init function but i am unable to access the points geometry
I had a demo working just using ThreeJS :
for ( let i = 0; i < mainContainer.children.length; i ++ ) {
const object = mainContainer.children[ i ];
if ( object instanceof THREE.Points ) {
I have set the pointCloud on entity
el.setObject3D('pointCloud', new THREE.Points( this.geometry, this.pointMaterial ));
i cannot access the geometry in the update function of the component, either using el.getObject3D('pointCloud') or using the id of the entity

Answer 1

As you set the object3D with setObject3D('pointCloud', new THREE.Points( ));, getObject3D('pointCloud') will retrieve the created THREE.Points instance.
The geometry is an attribute of the THREE.Points object:
<script src="https://aframe.io/releases/1.4.0/aframe.min.js"></script>
<script>
AFRAME.registerComponent("cloud", {
init: function() {
// create the points
const vertices = [];
for (let i = 0; i < 500; i++) {
const x = THREE.MathUtils.randFloatSpread(5);
const y = THREE.MathUtils.randFloatSpread(5);
const z = THREE.MathUtils.randFloatSpread(5);
vertices.push(x, y, z);
}
// create a geometry from the points
const geometry = new THREE.BufferGeometry();
geometry.setAttribute('position', new THREE.Float32BufferAttribute(vertices, 3));
// small grey points material
const material = new THREE.PointsMaterial({ color: 0x888888, size: 0.05 });
// setObject3D sets the points under the name 'cloud'
this.el.setObject3D("cloud", new THREE.Points(geometry, material))
},
update: function() {
// retrieve the THREE.Points object
const points = this.el.getObject3D("cloud");
// get it's geometry attribute
const geometry = points.geometry;
// log it
console.log(geometry)
}
})
</script>
<a-scene>
<a-entity position="0 1 -4" cloud></a-entity>
</a-scene>