Developable Surfaces - DevSrf

@Lowell Any updates on V6 being able to create developable surfaces? Making DevSrf available with the current functionality would be much better than nothing.

Previous question on this topic DevSrf for Rhino 6

Status is still the same. No new info.

Hi Lowell, is the status still as it was in 2016 ? Thanks , Mark

@markintheozarks - There’s a new command in the V6 WIP, DevLoft, that is moving toward some of that functionality.
I wasn’t quite ready to announce it since it’s still got some rough edges and hasn’t been tested very much except internally.
However, it is there and I’ll be working on it more now.


@Lowell Good news that a new command for developable surfaces is being worked on, though I’d be satisfied with DevSrf ported to V6…

However, the current version of DevLoft has a significant problem. It appears to force the surface to span the entire length of both rail curves, even when there is not a developable surface which spans he entire length of both rail curves. Here’s an example using the simplest developable surface, a section of a circular cylinder. DevLoftTest_DC001.3dm (98.2 KB) The rails are circular arcs which lie in parallel planes and on the same circular cylinder.

The exact solution for a developable surface between the rails is a section of a circular cylinder.

However DevLoft (in (6.0.17290.10121, 10/17/2017) creates a surface which significantly deviates from the developable surface.

DevSrf in V5 gives the correct solution.

We may get to porting DevSrf eventually.
The main feedback I’ve gotten about it is that it’s too complicated.

Understand about users considering DevSrf too complicated. But DevLoft needs fixing before official release.

A related buglet -


Is Devloft now oke?
and will devsrf be available for r6 or is it there already because I can’t find it