@objc func addBlock() {

        let grAnchor = try? self.gSession.resolveCloudAnchor(withIdentifier: self.cloudIdentifier)

        if let cloudAnchor = grAnchor {

            let box = SCNBox(width: 0.1, height: 0.1, length: 0.1, chamferRadius: 0)
            let node = SCNNode(geometry: box)
            node.position = SCNVector3(cloudAnchor.transform.columns.3.x, cloudAnchor.transform.columns.3.y, cloudAnchor.transform.columns.3.z)
            self.sceneView.scene.rootNode.addChildNode(node)

            let cloudAnchorRef = self.rootRef.child("cloud-anchors")
            cloudAnchorRef.setValue(["cloudIdentifier":self.cloudIdentifier,"hex":"#FFFFFF"])

        }
    }