Trajectory of a sphere

Questions
1

Hi
How to draw the trajectory of a moving sphere in three js?

2

is this what you Want:

const sphereGeometry = new THREE.SphereGeometry(1, 32, 32);
const sphereMaterial = new THREE.MeshBasicMaterial({ color: 0x0077ff });
const sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);
scene.add(sphere);
// Create a geometry for the trajectory
const trajectoryPoints = [];
const trajectoryGeometry = new THREE.BufferGeometry().setFromPoints(trajectoryPoints);
const trajectoryMaterial = new THREE.LineBasicMaterial({ color: 0xff0000 });
const trajectoryLine = new THREE.Line(trajectoryGeometry, trajectoryMaterial);
scene.add(trajectoryLine);
let time = 0;

function animate() {
    requestAnimationFrame(animate);
    
    // Update sphere position
    const radius = 20;
    const speed = 0.05;
    sphere.position.x = radius * Math.cos(time);
    sphere.position.y = radius * Math.sin(time);
    time += speed;
    
    // Update trajectory
    trajectoryPoints.push(sphere.position.clone());
    trajectoryGeometry.setFromPoints(trajectoryPoints);
    
    // Render the scene
    renderer.render(scene, camera);
}

animate();
3

Keep in mind position of camera, because when OP will implement your code, he will see black screen…

camera.position.z = 40; // ~
4

Yes ,That 's Right

5

Thank you i will try