ion.applyAxisAngle( _axis, 0.001 );

					// update the position
					_scale.setScalar( 0.02 );
					_matrix.compose( _position, _quaternion, _scale );
					sphereInstance.setMatrixAt( i * 2, _matrix );

					// raycast
					_raycaster.ray.origin.copy( _position );
					_raycaster.ray.direction.copy( _position ).multiplyScalar( - 1 ).normalize();

					// update hits points and lines
					const hits = _raycaster.intersectObject( mesh );
					if ( hits.length !== 0 ) {

						const hit = hits[ 0 ];
						con