code: function buildLidFaces() {
  
  			var start = verticesArray.length / 3;
  
  			if ( bevelEnabled ) {
  
  				var layer = 0; // steps + 1
  				var offset = vlen * layer;
  
  				// Bottom faces
  
  				for ( i = 0; i < flen; i ++ ) {
  
  					face = faces[ i ];
  					f3( face[ 2 ] + offset, face[ 1 ] + offset, face[ 0 ] + offset );
  
  				}
  
  				layer = steps + bevelSegments * 2;
  				offset = vlen * layer;
  
  				// Top faces
  
  				for ( i = 0; i < flen; i ++ ) {
  
  					face = faces[ i ];
  					f3( face[ 0 ] + offset, face[ 1 ] + offset, face[ 2 ] + offset );
  
  				}
  
  			} else {
  
  				// Bottom faces
  
  				for ( i = 0; i < flen; i ++ ) {
  
  					face = faces[ i ];
  					f3( face[ 2 ], face[ 1 ], face[ 0 ] );
  
  				}
  
  				// Top faces
  
  				for ( i = 0; i < flen; i ++ ) {
  
  					face = faces[ i ];
  					f3( face[ 0 ] + vlen * steps, face[ 1 ] + vlen * steps, face[ 2 ] + vlen * steps );
  
  				}
  
  			}
  
  			scope.addGroup( start, verticesArray.length / 3 - start, 0 );
  
  		}
docs: ///  Internal functions