deconstructing a surface into faces

Hi folks and happy 2014,

I have a sloped surface (or mesh) in Rhino which I am trying to "deconstruct" with Grasshopper and "triangulate" it if you will. I want to break it down into separate pieces, thus simplifying it. I then want each of those pieces to rotate in place so that they are parallel to the Cartesian grid and finally I want to extrude those pieces downward.

The picture I have attached is representative of the effect I want to end up with.

I should say I am an almost complete GH amateur but I am quite good with Rhino.

Big thanks

Eleftherios

Attachments:

Giants-causeway-in-ireland.jpg, 282 KB

Replies to This Discussion

Permalink Reply by David Rutten on January 3, 2014 at 2:48am

They're all hexagons right, because of the basalt?

If you're happy with perfect hexagons, then you can use a hex grid, then move the polygons to the correct elevation and extrude them again.

If you want the hexagons to be slightly less identical, then this may well be one of those few cases where Voronoi diagrams are actually called for.

David Rutten

david@mcneel.com

Attachments:

Hexagons.gh, 12 KB

Permalink Reply by Eleftherios Dousis on January 3, 2014 at 3:22am

I would prefer them not to be identical and not necessarily hexagons. The 'Mesh Edges' command shows I think a more random set of shapes that I would prefer to use instead of hexagons.

Thanks

Permalink Reply by David Rutten on January 3, 2014 at 3:57am

This file deformes the hexagons, it basically has a randomization+voronoi bit in the middle, otherwise it's the same logic.

Where do these mesh edges come from? Note that meshes only support triangles and quadrilaterals, so you'll never get a shape that has more corners than 4.

David Rutten

david@mcneel.com

Attachments:

Hexagons2.gh, 14 KB

Permalink Reply by David Rutten on January 3, 2014 at 4:01am

You can create a mesh from the surface directly, then get the edges of each face, project them onto XY then elevate them and extrude them:

David Rutten

david@mcneel.com

Attachments:

MeshFaces.gh, 12 KB

Permalink Reply by Eleftherios Dousis on January 3, 2014 at 9:58am

Thank you infinitely for your help thus far. The last entry is the effect I am looking for. However, my 'Polygon Center' component doesn't have the 'Ca' output that yours has in your screenshot. Is it a plugin I need to download or am I missing something?

Thanks in advance.

Eleftherios

Permalink Reply by David Rutten on January 3, 2014 at 11:59am

That output was added fairly recently. You should get roughly the same point with the second output.

David Rutten

david@mcneel.com

Permalink Reply by Eleftherios Dousis on January 4, 2014 at 11:06pm

Thank you so much for your help! I got the result I was looking for! Would be nice to have up to 5 corners but i'm essentially at my goal. Plus I do not want to trouble you any further.

Thank you!

Eleftherios

Permalink Reply by qiushi on January 3, 2014 at 3:15pm