Extrude a mesh and obtain a brep?

Grasshopper
1

Hello everyone.

I have this mesh, and I want to extrude it until XY plane and obtain the brep (solid) as a result, with no smooth of the terrain.

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image1607Ɨ711 128 KB

Is it possible? I attach the grasshopper file.
ExtrudeMesh.gh (19.2 MB)

2

I have various C#'s that do that (but itā€™s pure code - no native components of anykind). If you think that such a solution could be OK ā€¦ notify.

3

Hello
do you really need it to be Brep ? As the number of points is big I am not sure it is the best idea.

If you want a solid mesh it is quite basic Grasshopper.
Take a Naked Edge, project it to a plane. Make a quad mesh with the 2 edges.
Project the terrain on the plane
Join all meshes

image
image943Ɨ794 119 KB

extrude terrain.gh (11.4 KB)

And if you really want Brep, here with a regular quad mesh but you will have to count the number of points. But there are others ways.

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image1012Ɨ770 111 KB

extrude terrain brep.gh (10.3 KB)

3 Likes
4

No need:

Screen Shot 011
Screen Shot 0111653Ɨ514 161 KB

Screen Shot 012
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2 Likes
5

You Only using System.Ling;
or? Ect? For V.groupby?

6

V stands for the Mesh Topo Vertices (or Vertices if you like - after Vertices.CombineIdentical()). All that (as Laurent pointed out) given a regular quad mesh. If this is not the case you can use various other ways (like a classic ā€œList value spike detectionā€ etc etc).

Given the opportunity: TopoVertices and Vertices use different indexing (but thereā€™s R Methods ā€œfrom/toā€).

BTW: What means Ect?

7

Is there any possibility to extrude directly the mesh? Without converting it into a surface, what makes it a bit different.

8

Typically I donā€™t suggest using plugins but this one is one GH didnā€™t come with.

But then youā€™re asking for a brep, not a mesh result? :thinking:

Anyway,

Wombat plugin has an ā€˜extrude as meshā€™ component.
Mesh tools has a ā€˜mesh loftā€™ component for a more vanilla way of doing it where you can mesh-loft the naked edge of the terrain mesh to its planar/projected versionā€¦but then youā€™ll obtain a mesh not a brepā€¦soā€¦ :man_shrugging:

And your edge is a bit naughty:

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image1034Ɨ647 223 KB

Extrusions will be equally naughty.

Can you clean that edge?

Back to plugins, you can thicken the mesh with Weaverbird then boolean-trim that closed mesh, which is still a mesh, not a brepā€¦you can grab all mesh faces (polylines), make those surfaces, join all as a closed brep.

Donā€™t do it :slight_smile:

9

Thanks for the plugin! Iā€™ll try it

I tried to do it and Rhino crashed. I know it is an operation where many resources are required. However, I need that brep to obtain volumes of land to excavate, so it must be precise with Delaunay triangulation.

10

Any possibility to have Delaunay triangulation, at least in circle with radius 100? All left points can be approximated.