How to generate a triangular line grid based on a collection of points?

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Permalink Reply by Danny Boyes on October 18, 2009 at 8:47am

Have you looked into the Delaunay Mesh component or the Delaunay Edges found on the MESH tab in Triangulation.

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Permalink Reply by Jon Mirtschin on October 18, 2009 at 10:29am

I could be wrong (I didn't try this), but I don't believe Delaunay would wrap the underside of your dome (assuming you're subdividing an entire dome). 2d Delaunay basically operates on a projected plane.



If a non-grasshopper solution is acceptable, I added code for various geodesic domes into my Structural Drawing Plug-in, http://ssi.wikidot.com . If you need the curves in Grasshopper, they can be assigned to a curve group and scaled/translated as needed. If it's useful but not doing exactly what you need, let me know and I'd try to address it.

Cheers,

Jon http://www.youtube.com/watch?v=bfrljz-l8b0

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Permalink Reply by Niels De Temmerman on October 18, 2009 at 3:09pm

Hey Jon,

thanks for the tip. It is nice that you have added quite an extensive functionality for geodesic domes. Did you ever build one? I am researching deployable structures and have a student who will build and analyze deployable domes (cfr. Chuck Hoberman). I would be easier for me to have it all within grasshopper, because I need to add a lot of operations in order to turn an geodesic grid in a double layer scissor stucture.

You are right in saying that Delauney doesn't work for full domes, but there is a repetition in a full dome. there is great symmetry so there are only a few different elements, especially if you use a low frequency.

I tried to use SSI but couldn't get the trial version request command to work. mail wouldn't send.

A suggestion: would you deem it possible that you would create a grasshopper definition for your gesodesic domes, so everyone could use them, or would that be counterproductive...Because now there isn't a good working grasshopper definition that does what I saw SSI does on youtube. just my thoughts.

keep up the good work!

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Permalink Reply by Niels De Temmerman on October 18, 2009 at 9:01am

Hi Danny,

Yes I tried that but Grasshopper crashes or hangs when I try that. Could that have anything to do with the fact that there is a strange 'null' value in my point collection? maybe the Null causes the hanging of grasshopper...

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Permalink Reply by Danny Boyes on October 18, 2009 at 9:12am

Not sure. The data needs to be flattened in-order for it to be drawn correctly so maybe the lack of enough points in 4 of your 6 branches is causing the melt down. The image above was created by simply adding your E outputs to a flattened delaunay mesh component. Is the image what you expected?

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Permalink Reply by Niels De Temmerman on October 18, 2009 at 9:19am

This exactly what I expected. I have tried it before, but it didn't work. But, as you said, flattening is the answer. I flattened it before I connected it and it no longer hangs and it is what I wanted.

Thank you very much!

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