hetaStart: 0,
						thetaLength: twoPi
					};

					function generateGeometry() {

						updateGroupGeometry( mesh,
							new RingGeometry(
								data.innerRadius, data.outerRadius, data.thetaSegments, data.phiSegments, data.thetaStart, data.thetaLength
							)
						);

					}

					const folder = gui.addFolder( 'THREE.RingGeometry' );

					folder.add( data, 'innerRadius', 1, 30 ).onChange( generateGeometry );
					folder.add( data, 'outerRadius', 1, 30 ).onChange( generateGeometry );
					folder.add