Celtic Bunny

Upon subdividing a directly produced quad mesh ( http://www.grasshopper3d.com/photo/mesh-to-nurbs-polysurface-conver... ) from a uniform Kangaroo 1 MeshMachine remesh, I noticed that little weave-ready ribbons appeared:

Though the Mesh+ plug-in has a few "weave" components, they only make local loops between adjacent mesh faces.

So I did the bookeeping required to create little construction ellipses and little stubby start and end lines offset in and out from each mesh edge to allow a curve blend and then rail sweep of locally rescaled ellipses along those curves, with lots of control.

There are occasional tube self overlaps due to kinks that would require fixing in other software to 3D print the output.

Interestingly, the result is sometimes a single knot curve, more often a mere handful.

Replies to This Discussion

Permalink Reply by Nik Willmore on April 16, 2016 at 2:57pm

Official Tree Sloth plugin location is here:

http://www.bespokegeometry.com/2015/07/07/treesloth/

Milk Box is a forum group, not a plugin.

Permalink Reply by dvdrbls on April 16, 2016 at 8:39pm

really nice!

i am trying to understand the continuity part in order to be able to modify it even further, any tips or advice?

thanks!

Attachments:

MeshTriWeaveLoops_dvdrbls.gh, 29 KB
MeshTriWeaveLoops_dvdrbls.jpg, 528 KB

Permalink Reply by Nik Willmore on April 17, 2016 at 7:44am

Your mesh wasn't internalized so I recreated it by converting a Rhino surface to a mesh using custom settings to set a maximum edge length then triangulated it.

The bulge factor was set to an ineffective 0.1 in the pop-up selection menu.

Continuity between segments relies on using a curve blend and having little straight throwaway construction lines at the centers of each ellipse/polygon that have the same orientation except in 180 degree opposite direction in one face versus it's neighbor. They fully rely on the overall mesh edge normal for that determination and between two faces is the exact same overall mesh edge so they indeed line up, no matter what angle there is between the faces. The blend handles the ends being lined up with some sacrifice of not being able to control what the middle of the curves do when angles get wild or triangles get skinny.

Permalink Reply by Kim hauer on April 17, 2016 at 11:11am

1.Is there a way to involve the other 5 cube faces?

2.I suspect there also would not be any continuity of the geometry around to the adjoining face

Permalink Reply by Nik Willmore on April 17, 2016 at 2:03pm

Make one mesh, but it will have to be a real join not just a formal one. I assume mesh join itself will weld the vertices though. The continuity is guaranteed but the swing of the tubes in 3D space may intersect unpredictably.

Permalink Reply by Nik Willmore on April 17, 2016 at 2:53pm

Recreating your mesh required Weaverbird Weave Back (Mesh From Lines). Since you have only a few mesh faces per cube face which then forms a 90 degree angle, this is actually an extreme example compared to a nice smooth MeshMachine model. I disabled slow NURBS tube making to fast preview slider changes with a mesh pipe and noticed a left out or intersecting loop at each cube corner so I deleted those and got something reasonable as a weave. An mesh octahedron or especially icosahedron is a more natural primitive for a regular mesh, since your cube has irregular triangles.

Permalink Reply by Nik Willmore on April 17, 2016 at 3:50pm

An icosahedron or octahedron mesh avoids the fun mouse mirror effects that an unnaturally triangulated mesh cube suffers. Now the whole script could be revamped to do quad meshes but Rhino/Grasshopper won't give quad remeshing like it will for triangles via MeshMachine. If I was motivated it could be generalized for any polygon face size using the same connectivity rules in each of the two cases I've addressed.

Permalink Reply by Kim hauer on April 17, 2016 at 4:58pm

Very Knot like! :)

https://web.njit.edu/~kappraff/KnotPlot.pdf

Permalink Reply by Nik Willmore on April 17, 2016 at 4:54pm

Oh wow, because the ring system has so well defined single ring units with no self-overlap (except some kinks in extreme cases) that also have well defined overlaps between each other when the tube diameter is big enough, they can not only be Boolean unioned but also mass filleted in Rhino.

Permalink Reply by Kim hauer on April 17, 2016 at 5:11pm

I agree! there is some nice geometry happening here! I can see one of those gold baubles, on a chain, hanging around a neck!

Permalink Reply by dvdrbls on April 17, 2016 at 6:14pm

wow those are some pretty nice results!

Permalink Reply by Kim hauer on April 17, 2016 at 6:31pm

the "knitted cube" was unintended. Somehow the subdivisions just kept increasing from the original cube+mesh join from above!