Rotate around itself

Questions
1

Hi, I load model.glb and I set position is (1,0,-2).
Now, I use this code to rotate but it show on screen changed position although I check log I see after rotating object keep position (1,0,-2).
I want to just rotate around itself and keep position (1,0,-2) when show on screen

const pivot = draggableModel.position.clone(); // use object position as the pivot point
pivot.y += 0.25; // move pivot up by half of object height (adjust as needed)
console.log(“1:”,draggableModel.position)
// Translate the object to the pivot point
draggableModel.translateX(-pivot.x);
draggableModel.translateY(-pivot.y);
draggableModel.translateZ(-pivot.z);
console.log(“2:”,draggableModel.position)
// Rotate the object around the Y-axis
const angle = THREE.MathUtils.degToRad(90);
const axis = new THREE.Vector3(0, 1, 0);
const rotationMatrix = new THREE.Matrix4().makeRotationAxis(axis, angle);
draggableModel.applyMatrix4(rotationMatrix);

  console.log("3:",rotationMatrix)
  // Translate the object back to its original position
  draggableModel.translateX(pivot.x);
  draggableModel.translateY(pivot.y);
  draggableModel.translateZ(pivot.z);

2

Instead of pivot being a vector, make it a group. Ie:

const pivot = new Three.Group();
pivot.add(model);
scene.add(pivot); // NOTE Do not add model directly to the scene, just the pivot group

model.position.set(0.0, -0.25, 0.0): // NOTE Position model within pivot so that it’s centre of gravity is in the centre of the pivot group. You can use Box3.getSize to do it more accurately too.

Now if you apply rotations to model - it’ll rotate locally within the pivot only (according to its position within the group.) And applying rotation to pivot group will rotate the entire thing in world space. No need for translations or matrix magic :relieved::pray:

3

Simple solution is into 3ds max or blender change vertices coordinates to center.

4

See from the Collection of examples from discourse.threejs.org

BeginnerExample step 3 Squirrel