phereGeometry(sphereRadius, sphereWidthDivisions, sphereHeightDivisions);
    const sphereMat = new THREE.MeshPhongMaterial({color: '#CA8'});
    const mesh = new THREE.Mesh(sphereGeo, sphereMat);
    mesh.castShadow = true;
    mesh.receiveShadow = true;
    mesh.position.set(-sphereRadius - 1, sphereRadius + 2, 0);
    scene.add(mesh);
  }

  class ColorGUIHelper {
    constructor(object, prop) {
      this.object = object;
      this.prop = prop;
    }
    get value() {
      return `#${this.object[this.