Mesh offset by face normals to create inner surface (apply thichkness)

Hi all,

I have created a folded plate structure, as seen here below. It consists of a number of planar quad plates, which are to be assembled along their edges. Each polygon is closed and planar.

My problem arises, when trying to give each plate a thichkness. I first tried with Weaverbirds "Offset mesh", but that resulted in variabel thicknesses aka non planar results. The offset should be in the direction of the face normals. Any ideas of how to do this?

I realize there might be some problems in joining the edges at a single vertex, since the valence at each node is 4, but I am thinking of cutting away a small piece of material here, to compensate for this.

Any help would be greatly appreciated!!

/ Kirsten

Attachments:

folded plate structure_grasshopper forum.gh, 61 KB

Replies to This Discussion

Permalink Reply by Daniel González Abalde on September 2, 2015 at 7:13am

You must attach the geometry in 3DM format.

Permalink Reply by Kirsten Lægaard on September 2, 2015 at 7:19am

Sorry!

I just Internalized the data and added the file again.

Does this work?

Attachments:

folded plate structure_grasshopper forum.gh, 67 KB

Permalink Reply by Daniel González Abalde on September 2, 2015 at 8:03am

Well, this is difficult if your looking to make a clean mesh. But if you only want a 3d representation, you can use this approach, extruding breps on each side separately. Does that serves?

Attachments:

foldedplatestructure_grasshopperforum (1).gh, 91 KB

Permalink Reply by taz on September 2, 2015 at 9:04am

This is old, but the logic is sound for creating clean offsets via meshes... You'll need Weaverbird.

http://www.grasshopper3d.com/forum/topics/creating-a-faceted-structure

Permalink Reply by taz on September 2, 2015 at 9:08am

Alternatively Mesh(+) is the new game in town for mesh manipulation and has integrated some of the features of Weaverbird, so you can give either a try straight out of the box.

Look under the Edit tab:

http://www.food4rhino.com/project/mesh?ufh

Permalink Reply by taz on September 4, 2015 at 2:35am

OK, so after thinking about it I realize what I posted was not helpful at all, but now I think I understand what you're trying to do... You want to create non-intersecting faces of a prescribed thickness (i.e. like for a physical material).

This is based off centerline geometry using Mesh(+)2.0 components. You may have to reattach your mesh again, it doesn't seem to want to stay internalized. Thickness shown exaggerated.

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