×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Unfolding of Surfaces

Unfolding of Surfaces

Unfolding of Surfaces

(OP)
Dear all,
I need to create plots for "unfolded" 3dimensionally-curved surfaces. Does anyone know a way to tackle that with Rhino? Probably accept a certain "crinkle" tolerance and split surfaces manually if there is no other way? Who found a way to deal with such an issue? Any help is appreciated, thank you.
Markus

RE: Unfolding of Surfaces

Hi,

As far as I can understand you are trying to construct complex surfaces out of cutout planes as I do with the sails for the sailing boats. I am extracting the isoparms of a designed sail along the stitch lines with "Extract Isoparms" command (some times I prefer to use "Contour" command for linear cut sails). Then I build up linear (flat) developable surfaces using this lines. Then with "unroll" command I can have templates for the sail cuts. I belive you can derivate the solutions for your specific geometrical objects in the same manner. For instance Iwould try to cut a sphere to some amout (amount depens to degree of final smoothness to achieve on sphere) of identical triangles to be able to have the templates for cutout planes. Also you can try "polygon mesh" with some more automatised way

RE: Unfolding of Surfaces

Fatgun,
This method looks interesting, I'm seeing it as a quick way to mock up models with complex surfaces in them. Imagine slicing up your 3D model by extracting the isoparms and building mini surfaces as you described, then unrolling them and using them as templates for cutting sheet material to build the real model.  Seems to me like a nice quick way to make a 3D mockup of you idea. This helps in getting the proportions of what you are building right.  Thanks for the idea.

Cheers,


Tom  

you could even do up some internal ribbing out of flat sheet to add some strength to the model.  this gets better and better...thanks

RE: Unfolding of Surfaces

(OP)
OK, so I manually have to loft developable surfaces from those isoparms created...wouldn't it be handy to create flat surfaces from the polygon mesh?
How can I get rid of the underlying NURBS-information and just create truly flat surfaces using the polygon mesh?

RE: Unfolding of Surfaces

Hey news!

 Ive seen a plug in that does this very task. Theres a link to it on the Rhino site somewhere. Its to do with shipbuilding, I cant remember the name. It works a treat.

 Rhino can only 'unroll developable surface' where it is a simple surface and for example a half ball surface cannot be unrolled. This plug in can handle surfaces that curve in two directions at once.

 However, I dont think it unrolls multiple or 'stitched' surfaces that may comprise of a part. Im not sure, its been a while.
 You can get a demo that lasts 30 days last time I looked.

 See ya

Sirius.

RE: Unfolding of Surfaces

(OP)
Sirius,
thank you for your note, I think the software is called "Expander", and might be what I am looking for...I'll try the 15 days demo and see...
BTW, any other hints are still appreciated.
Cheers

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources