res/cube/Bridge2/';
				const urls = [ r + 'posx.jpg', r + 'negx.jpg',
							 r + 'posy.jpg', r + 'negy.jpg',
							 r + 'posz.jpg', r + 'negz.jpg' ];

				const textureCube = new THREE.CubeTextureLoader().load( urls );

				scene.background = textureCube;

				// plane particles

				const planePiece = new THREE.PlaneGeometry( 10, 10, 1, 1 );

				const planeMat = new THREE.MeshPhongMaterial( {
					color: 0xffffff * 0.4,
					shininess: 0.5,
					specular: 0xffffff,
					envMap: textureCube,
					side: 