d it. This will occlude the VR scene with the 
        // real world.
        let material = new THREE.MeshBasicMaterial({ color: 0xffffff, side: THREE.FrontSide });
        material.blending = THREE.CustomBlending;
        material.blendEquation = THREE.AddEquation;
        material.blendSrc = THREE.ZeroFactor;
        material.blendDst = THREE.ZeroFactor;
        meshMaterials.push(material);
      }
    }

    showMeshTriangles.addEventListener('input', element => updateState());

    // Suppress XR even