A groin vault is an intersection of two barrel vaults at right angles. A barrel vault , in its simplist form is just a tunnel with a round surface (half a barrel).
I am trying to model one of these and having a point of view problem. The method that I am using is to make two half barrels (9 CPs per arch) and and enough segments so that I can intersct each arch with the one on the crossing piece. I then manually line up the segments. I remove the un needed interior patches, draw in the crossing splines formed by the intersections and then weld the CPs at the intersecting points. In wireframe view the groin vault is perfect. In shaded view it is quite a mess. The joined edges are all formed of three point patches and render with a funny puffyness. Even texturing does not hide the anomalies. I cant seem to "see" another way to model this type of construct.
Anyone have a different angle that I can look at this problem from?