code: function buildSideFaces() {
  
  		var layeroffset = 0;
  		sidewalls( contour, layeroffset );
  		layeroffset += contour.length;
  
  		for ( h = 0, hl = holes.length; h < hl; h ++ ) {
  
  			ahole = holes[ h ];
  			sidewalls( ahole, layeroffset );
  
  			//, true
  			layeroffset += ahole.length;
  
  		}
  
  	}
docs: Create faces for the z-sides of the shape