eight );
			renderer.setPixelRatio( window.devicePixelRatio );
			document.body.appendChild( renderer.domElement );

			// camera
			const camera = new THREE.PerspectiveCamera( 30.0, window.innerWidth / window.innerHeight, 0.1, 20.0 );
			camera.position.set( 0.0, 1.0, 5.0 );

			// camera controls
			const controls = new OrbitControls( camera, renderer.domElement );
			controls.screenSpacePanning = true;
			controls.target.set( 0.0, 1.0, 0.0 );
			controls.update();

			// scene
			const scene = new THREE.