@polygonjs/polygonjs/dist/src/core/LookAt.js

node-based WebGL 3D engine https://polygonjs.com

"use strict";
import { Vector3, Matrix4 } from "three";
const t = new Vector3();
const _m4 = new Matrix4();
export function quatLookAt(position, targetPosition, up, target) {
  _m4.lookAt(targetPosition, position, up);
  target.setFromRotationMatrix(_m4);
}
export class CoreLookAt {
  static applyLookAt(object, target, invert) {
    if (invert) {
      t.copy(object.position);
      object.position.copy(target);
      object.updateMatrix();
      object.lookAt(t);
      object.position.copy(t);
      object.updateMatrix();
    } else {
      object.lookAt(target);
    }
  }
}