03 remove Stranded vertices and raise rims

Stranded vertices need to be cleaned away from the long edges, otherwise when the top-left corner is lifted up those lengths would buckle around interrupting vertices. Groups of stranded vertices along a single edge can be grabbed in a selection and then Collapsed down to one. Using Target Weld that single vertex can then be welded to another vertex at the top or bottom of the length. Once tidied, we can grab all the vertices and lift them up with the move tool. With the ‘polygon’ selection active in Polyedit, select the rim areas in the object and click Extrude Polygons.