Rhino definitely needs a tool that could handle such cases. The current tools are limited in a certain way in this scenario:
- “Sweep 1 rail” and “Network surface” both produce overly-complex multi-span surface;
- “Sweep 2 rails” (when the two profile curves are used as a rail instead) somehow is able to “almost” do the job, but the problem is that it expands the width of the surface, failing to maintain same width across the entire middle curve;
- “Extrude along curve” can’t use two input profiles, so it either extrudes the starting or the end profile.
- “Surface from 2, 3 or 4 edge curves” (“EdgeSurf”) produces a weird shape that’s considerably narrower than the input curves. On top of that, it’s pick-dependent, so the user must try to pick the input curves in various order to be able to achieve a non-twisted output.
People are forced to use “hacks” to achieve what should have been the (not yet existing) “Simple straight” option in “Sweep 1 rail” or “Sweep 2 rails”. Here is a quick video tutorial showing how I handle such cases:
