Rhino’s Blend srf does not respect conditions at the extreme surface. It is true that you can adjust the handles, but it is inconvenient and imprecise. With Xnurbs the connection is perfect, as you can see. [blend srf so and so] Blend srf problem.3dm (569.8 KB)

I do not know why you would try to do this that way in in Rhino, just use the tool correctly. [image] -Pascal

Blend Srf: little problem

Rhino_Bulgaria (Bobi) March 30, 2021, 4:32pm 5

I and other people often requested this feature for years. Plus many others regarding vast improvements of “Blend surface”. Example: