Exclude naked edges of a mesh

Grasshopper
1

GridDiagonals.gh (8.3 KB)
GridRhino.3dm (32.7 KB)

Hi all,

I have a mesh that I created from a manually drawn surface in Rhino. Then I used “DiagonalizeMesh” component to convert the rectangular grid to diagonal. I would like to select all the grid edges (in this case all the diagonal) except of the outer perimeter ones (parallel to X and Y coordinates).

I am still new to Grasshopper environment and would highly appreciate if someone can suggest a way of doing this.

All the best,
KR

2
21348×741 237 KB

2

GridDiagonals_2021Sep24a
GridDiagonals_2021Sep24a1545×611 128 KB

GridDiagonals_2021Sep24a.gh (20.0 KB)

This works with or without the Weaverbird’ components. Surface is internalized, no need for .3dm file.

1 Like
3

Use NGon DiagonalMesh is better

image
image1368×575 176 KB

2 Likes
4

If your diagonalized mesh’s vertices were properly welded, you could use Mesh Edgesto get the interior edges(E2)which is what you want…

Canvas at 18;56;14
Canvas at 18;56;141183×659 169 KB

GridDiagonals_re.gh (8.3 KB)

3 Likes
5

Hi Joseph,

That is great. Thank you for the solution presented.

6

Hi Seghier,

Thank you for the reply. By far this solution works best for my case.

7

Hi HS_Kim,

Thank you for the unique methodology. It also works.

8

If you zoom in you can see why the edges appear to be naked.:

grafik
grafik864×554 3.25 KB

It seems to use slightly different vertices for the mesh creation. I would call this a bug. Maybe @DanielPiker knows(and cares :)) why this is happening.
Also Petras’ version seems to suffer from this but less(you can see by zooming in) So probably all this is also a tolerance issue.
Here my clumsy C# attempt(if someone cares):
grafik
grafik1419×618 93.4 KB

File:20210925_DiagonalizeMesh.gh (8.2 KB)

3 Likes
9

Thanks for pointing this out,
Yes , this looks an easy fix. I’ll get the component updated.

2 Likes