Developable Hulls

For unrolling developable surfaces, Rhino has an “unrollsrf” command. Rhino also has a “devsrf” plug-in (which is free from https://www.food4rhino.com/app/devsrf), and Orca3D has two different developable hull assistants for creating developable hulls.

One of the Orca3D developable hull assistants allows you to define a chine hull in much the same way the planing hull assistant works (overall dimensions, some angular inputs, etc.), and then it uses Rhino’s devloft command to try to loft a developable surface between the sheer and chine, inner and outer chine (if you have a chine flat), and the chine and centerplane.

The other developable hull assistant takes a very different approach, trying to define the hull with a series of parts of cones and cylinders. You start by defining a chine curve, and there are various inputs for controlling the apexes of the conic surfaces, and planes to trim them off (e.g., the centerplane or a planar sheerline). The advantage of this approach is that it creates exactly developable surfaces, but it can be a bit difficult to master.