Modify the position of a point cloud and an associated trajectory

Questions
1

Hello,
Here is my problem: I have a point cloud (pcd format file) that I imported into three js. I moved my point cloud (rotation + position). I have the trajectory of a robot which moves in this point cloud but since I moved the point cloud, how can I apply the new position to my trajectory? Thanks for your help

2

For me it is quite unclear what you ask for.

Nevertheless, if you add the robot as a child object of the cloud, then the robot (and its trajectory) will move together with the cloud, independent on how you reposition and rotate the cloud.

3

Thanks for your help, but how do I set this up?
For now I have a cloud that I import into three js like this:

// instantiate a loader
const loaderPCD = new PCDLoader();

// load a resource
loaderPCD.load(
	// resource URL
	'static/models/2106.pcd',
	// called when the resource is loaded
	function ( points ) {
        //points.geometry.center();
        
        points.rotateY(4.8);
        points.rotateX(3.1);
        points.rotateZ(-0.1);
        points.position.x = 1.3;
        points.position.y = 6;
        points.position.z = 6;
		scene.add(points);

	},
	// called when loading is in progresses
	function ( xhr ) {

		console.log( ( xhr.loaderPCD / xhr.total * 100 ) + '% loaded' );

	},
	// called when loading has errors
	function ( error ) {

		console.log( 'An error happened' );

	}
);

My robot is a ply file imported in the same way:

function loadRobot(){

    loader.load(
        'static/models/car.ply',
        function (geometry) {
            geometry.computeVertexNormals()
            const material = new THREE.MeshPhysicalMaterial({
                color: 0x049ef4,
                metalness: 0.5,
                roughness: 0.5,
                // transparent: true,
                transmission: 0.5,
                side: THREE.DoubleSide,
                // clearcoat: 1.0,
                // clearcoatRoughness: 0.25,
            })
            meshRobot = new THREE.Mesh( geometry, material );
            meshRobot.position.x = 0.5; //RED
            meshRobot.position.y = - 0.9; //green
            meshRobot.position.z = - 0.12; //BLUE - 0.12
            meshRobot.scale.multiplyScalar( 0.001 );
            meshRobot.rotateX(Math.PI / 180)
            scene.add(meshRobot)
         
            //moove the robot
          
            //moove()
    
        },
        (xhr) => {
            console.log((xhr.loaded / xhr.total) * 100 + '% loaded')
        },
        (error) => {
            console.log(error)
        }
    )
    
}

Finally regarding the trajectory I proceed like this:

const points = [ 
    new THREE.Vector3(0.000118954, 0.001054873, -0.000306402),
    new THREE.Vector3(0.000777644, 0.001525318, -0.000664352),
    new THREE.Vector3(0.000707381, 0.002000148, -0.000671897),
    new THREE.Vector3( 0.000860078, 0.003138441, -0.000428472 ),
    new THREE.Vector3(0.000831843, 0.004344346, 0.000032551),
    new THREE.Vector3(0.002976510, 0.005033887, 0.001953103),
    new THREE.Vector3(0.004688929, 0.005484502, 0.004914966),
    new THREE.Vector3(0.005369600, 0.005044235, 0.008556681),
    new THREE.Vector3(0.003458110, 0.015809765, 0.009683169),
    new THREE.Vector3(0.001738887, 0.027185621, 0.011905815),
    new THREE.Vector3(0.002296457, 0.041347280, 0.011081150),
  
];

const path = new THREE.CatmullRomCurve3(points);

const pathGeomtry = new THREE.BufferGeometry().setFromPoints(path.getPoint(50));
const pathMaterial = new THREE.LineBasicMaterial({color:0x00ff00});
const pathObject = new THREE.Line(pathGeomtry,pathMaterial);
scene.add(pathObject);

And in the animate function:

  const time = Date.now();
    const t  =(time/2000 % 12)/12;
    const position = path.getPointAt(t);
    if(document.getElementById("robot").checked) var device = meshRobot;
    else var device = cube;
   
   
    device.position.copy(position);

    const tangent = path.getTangentAt(t).normalize();
    device.lookAt(position.clone().add(tangent));

Thanks for your help

4

Still not clear what you’re asking.

Throw that junk into a jsfiddle or a glitch and try to articulate the problem more clearly, and we can look into it further.

Here’s a glitch you can “remix” and put your code into script.js