I tried to pick-up objects and it didn't work out.

[volcanoqq]

normal.video.mp4

Like in the video, my manipulator tries to grasp the object, but visually they do not collide, why does the object bounce away.

[volcanoqq]

`

  // Mechanical arm
  const left = editor.scene.getObjectByName("左抓手");
  const right = editor.scene.getObjectByName("右抓手");

  physicsManager.createRigidBodyByObject(left, {
    shape: "convex",
    collisionFlags: 2,
  });
  physicsManager.createRigidBodyByObject(right, {
    shape: "convex",
    collisionFlags: 2,
  });

  left.body.setFriction(1);
  right.body.setFriction(1);

  // Objects that need to be grabbed
  for (let i = 1; i <= 6; i++) {
    const obj = editor.scene.getObjectByName("电池" + i);
    physicsManager.createRigidBodyByObject(obj, {
      shape: "convex",
    });
  }

`

`

//PhysicsManager.js

import { AmmoPhysics } from "@enable3d/ammo-physics";
import * as THREE from "three";

export class PhysicsManager {
  constructor(editor) {
    this.editor = editor;
    this.physics = new AmmoPhysics(editor.scene);
    this.physics.debug.enable(true);
  }

  createRigidBodyByObject(object, options = {}) {
    this.physics.add.existing(object, options);
  }

  update(delta) {
    this.physics.update(delta * 1000);
    this.physics.updateDebugger();
  }
}

`

[yandeu]

Have you looked at this example?
https://enable3d.io/examples/standalone/pick-up-objects.html

I highly recommend using a box shape for the bricks.
And a compound of box shapes for the crane.

Maybe you also want to change the fixedTimeStep in https://enable3d.io/docs.html#physics-configuration.

[volcanoqq]

Yes, I've seen the example of pick-up objects, but my animation used tween.

If you use box shape to create, there will be an object rotation mismatch problem.

In this issue of mine at (https://github.com/enable3d/enable3d/issues/365)

What does fixedTimeStep do, and why do I need to change it?

[yandeu]

What does fixedTimeStep do

See the bullet manual:
https://github.com/bulletphysics/bullet3/blob/master/docs/Bullet_User_Manual.pdf