I set up a flat vertical surface that forms a u-shape to be blended with a flat horizontal surface. (See pix.) I made a two rail sweep were the lower rail was modified to pass through the quadrants of the desired profile curves so that when I used the tangent blend option I could apply the same adjustment to all three sides and the added shapes at the corners. This seems to give a fairly clean surface but I get some little anomaly. When I turn on points to inspect the surface there’s always a few points that seem out of place - not where they’re expected to be.
ArgoFlex5.3dm.zip (144.9 KB)