   renderer.setAnimationLoop(null);

          renderer.vr.enabled = true;
          renderer.vr.setAnimationLoop(animate);
          
          _loadPlantMeshes()
            .then(newPlantMeshes => {
              plantMeshes = newPlantMeshes;

              session.addEventListener('planeadd', _planeadd);
              session.addEventListener('planeremove', _planeremove);
              /* planeTracker = session.requestPlaneTracking();
              planeTracker.onplanes = _onPlanes; */
            })
  