OK, so I dug a little deeper, and here are my findings. I’m not sure if this is accurate, but I think that in order for this to work, you need to:
Make sure that you are in box mode, not smooth mode (Tab), because smooth mode will make Rhino think that there are 5 edges - I don’t know enough about how Sub-D works to explain that
Use the Sub-D edges as the rails and the two curves as the sweep shape.
Make sure that you select ChainEdges for the rails.
But this is most certainly in dire need of a tune-up!
Hi @theoutside
I know you are not on the programming side of things, but I know you’ve been using the Sub-D tools aquite a bit, so maybe you know who could/should take a look at this? Why do we need to go to box mode to get SubDSweep2 to recognize the correct number of edges and make the “right” solution OOTB? Shouldn’t the command behave the same in box and smooth mode?
I think the key is, if you want to work in smooth mode you have to make sure your curves touch a vertex in smooth mode… if it has to guess it can guess wrong.
I redid the example above and making sure the curves are snapped correctly, it worked as expected.