Help to 'Unroll Developable Surface'

Hi guys!
I would like som help since i currently run Rhino in Mac only.
(havent got around to get a Win OS to run in Bootcamp on my Mac and install my original win license).

The eval for Mac doesnt support the ‘Unroll developable surface’-command yet. Therefor i would like someone to possibly help unroll develop my file attached onto a flat surface in Win license and then mail me the file (or put here).

I would really appreciate it!
Thanks!parabol.3dm (94.7 KB)

Your surfaces are doubly curved - not developable - and thus cannot be unrolled by UnrollSrf…


Could it work with a polygon then, since built with ‘flat’ triangels?
file attached with two “cake-piece” poly’s.
Should work, although more or less accurate but happy with anything you can get out of it. Thanks!parabol1.3dm (99.2 KB)

I’m not sure what you are trying to achieve here, but several things may be worth noting:

  1. Currently you cannot unroll meshes in Rhino.

  2. You could convert your mesh into surfaces using MeshToNurb and try to unroll that, however, if you have a lot of triangles, the result will not be what you want - read here before proceeding.

  3. Just for reference, your Blender-created mesh is about 17 billion kilometers from the origin in Z - completely unusable in Rhino at that distance.

What you can do is to create a tessellated surface composed of flat panels approximating your object and unroll that - in the example attached, I converted the edges to polylines and used Loft and Rotate/Copy to create the sections, then joined them together and unrolled them with Explode=No…


parabol1-TessUnroll.3dm (524.2 KB)

Not sure about the Mac version but there is the _Squish command under Windows which, in case the mesh is perfectly unrollable, will give some accurate results. In case of the geometry posted above, i think that the results are usable too but i have no idea how accurate they are. example file using a mesh and _Squish: parabol.3dm (356.4 KB)

Alternatively double curved single surfaces can be unrolled almost perfectly into a mesh using the LSCM algorithm of the texture editor.


I knew it! ;D
Thank you, Clement, this is really what i was looking for! Thanks again!
(Did work on Mac too).
Its interesting to see the result, and how it twists and makes some kind of zig-zag. near the nib end.
Probably not a super easy equation but as usual; Rhino delivers! =)