Trasnforming the border lines from the polygons of a mesh into a curve network

Hi, I have a surface mesh and I want to transform his wireframe into UV curves (not segments) all the way from border to border. If I extract the wireframe I get a group of small lines the size of the border of the polygon, what I´m looking for is to merge all this lines into one curve according to the each direction.

I provide the mesh wich I want to transform into UV curves .

Thank you for your time!

Attachments:

Mesh problem.3dm, 98 KB

Replies to This Discussion

Permalink Reply by Florian Frank on March 5, 2013 at 8:54am

I know it's maybe a stupid way to do it...but it might be enough for what you need it?

If not it could get tricky...you have to do a slight heavy algorithm that looks for the discrepancy between the edge directions on each vertex and decide which edge has to go where...in GH pretty heavy to solve.

But maybe this works for you ;-)

Cheers FF

Attachments:

isoCurves.gh, 4 KB

Permalink Reply by Andrés Tricnina on March 5, 2013 at 11:37am

Hi Florian!

Thank you very much for your answer. I gave a try to your definition and it seems to work nicely besides the loss of some detail at the anchor points maybe because the curves aren´t identical to the border of the mesh polygons.

A similar aproach that I found is to project a network of curves on top of the mesh. This network must be the same that the primitive network form wich the deformated mesh comes. For instance, a squared pattern mesh> deformation of this mesh with kangaroo> projection of a network of curves equal in span to the original mesh polygons. This seems to work great but as your example there is some loss of detail. I´ll keep researching.

Lots of thanks!

Permalink Reply by Florian Frank on March 5, 2013 at 11:52am

yes indeed some details get lost...they will get lost in any of those approaches, where you don't actually get the edges directly from the mesh.

You can subdivide the mesh further with for example weaverbird...this will increase the details a lot on the nurb surface >> isocurves...it might work with the kangaroo method as well

if you have some days to wait i can write a little code to extract the actual mesh edges in the right order, which you can then simply join in gh or rhino and do whatever you want...so if you can wate a little i can help you out with this.

Best regards

Permalink Reply by Andrés Tricnina on March 6, 2013 at 2:23am

Wow Florian! that would be awesome, I bet it could be useful for a lot of users too. Take your time, I´m not in a hurry. LOTS OF THANKS!!!

Permalink Reply by Florian Frank on March 6, 2013 at 8:12am

if its useful for a lot of other people i think i'll start this little project...i'll let you know once i've finished with the script ;-)

Permalink Reply by Florian Frank on March 6, 2013 at 2:30pm

Hi Andres,

It was less work then i expected....so i did a small script, that decomposes the edges in the right order, so you can join them and you'll have nice UV curves.

Did some shit afterwards, because the last curves are not exported...it's because i was too lacy with the script ;-)

Also this Script works only with Meshes that has only Quads...and might have issues with imported Meshes, because the order of the Vertices might got chaotic...i know there is a much more cleaner and rock solid way to do it, if i loop trough all the edges and check for vector discrepancy, but i thought this might do the trick for you.