title: How to group Buffer Geometry Object in Autodesk Forge
body: <p>I wondering is it posssible to add group of model group from scenebuilder. Initially I used a overlay.addMesh but I wanted to interact with a custom object that I created. Unfortunately the object must be a grouping. This is my code. Nothing appear on my Viewer.</p>
  <pre><code>this.sceneBuilder = await this.viewer.loadExtension(
    &quot;Autodesk.Viewing.SceneBuilder&quot;
  );
  this.modelBuilder = await this.sceneBuilder.addNewModel({
    modelNameOverride: &quot;Beacon&quot;,
    conserveMemory: false,
  });
  const sphereGeometry = new THREE.BufferGeometry().fromGeometry(
    new THREE.SphereGeometry(5, 8, 8)
  );
  const sphereMaterial = new THREE.MeshPhongMaterial({
    color: new THREE.Color(0.647, 0.165, 0.165),
  });
  
  this.meshBeacon = new THREE.Mesh(sphereGeometry, sphereMaterial);
  this.meshBeacon2 = new THREE.Mesh(sphereGeometry, sphereMaterial);
  this.meshBeacon.matrix = new THREE.Matrix4().compose(
    position1,
    quaternion,
    scale
  );
  this.meshBeacon2.matrix = new THREE.Matrix4().compose(
    position2,
    quaternion,
    scale
  );
  
  this.group = new THREE.Group();
  this.group.add(this.meshBeacon);
  this.group.add(this.meshBeacon2);
  console.log(this.group);
  this.group.dbId = 666666;
  this.modelBuilder.addMesh(this.group);
  </code></pre>