docs: public final void getWorldPickRay(Vector3f origin, Vector3f direction)
      {
          GVRSceneObject owner = getOwnerObject();
  
          if (owner == null)              // should never come here, picker always
          {                               // owned by GVRGearCursorController pivot
              owner = mScene.getMainCameraRig().getHeadTransformObject();
          }
          Matrix4f mtx = owner.getTransform().getModelMatrix4f();
          origin.set(mRayOrigin);
          direction.set(mRayDirection);
          origin.mulPosition(mtx);        // get ray in world coordinates
          direction.mulDirection(mtx);
          direction.normalize();
      }