Help to 'Unroll Developable Surface'


#1

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)


#2

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

–Mitch


#3

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)


#4

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…

–Mitch

parabol1-TessUnroll.3dm (524.2 KB)


#5

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.

c.


#6

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! =)