How to triangulate a triangular surface

I know there are ways to triangulate a surface in a conventional way, like the images on the left and in the middle. But I'm trying to triangulate a triangular panel so each sub-panel is approximately same size triangle, like the one on the right. Is there a relatively straightforward way of doing it?

Thanks in advance for answering!

Replies to This Discussion

Permalink Reply by Rémy Maurcot on August 20, 2012 at 11:10am

Hi Darren please look this post:
http://www.grasshopper3d.com/forum/topics/divide-srf-logical
maybe help you.

Permalink Reply by Darren Chang on August 20, 2012 at 11:36am

hi Remy, thanks for replying. I tried your code by selecting the surface, but my computer stalled.

Permalink Reply by Andrew Heumann on August 20, 2012 at 11:57am

If your starting shapes are truly triangular, you can use weaverbird's "split polygon subdivision" component to calculate a triangular subdivision.

Permalink Reply by Darren Chang on August 20, 2012 at 12:55pm

Hi Andrew,

Weaverbird only works in mesh, right? I have to generate the sub-division in mesh, convert them back to nurbs, and then work on them. I am looking for something that is more automated. I have hundreds of panels to process.

And my triangles are actually warped surfaces, so they are not "truly triangular". This makes the mesh to start with already messy

Permalink Reply by Giulio Piacentino on August 20, 2012 at 2:29pm

Hi Darren

I'm Weaverbird's author. In this case I would then use something curstom made, such as the great definition Andrew himself posted here:

http://www.grasshopper3d.com/forum/topics/dividing-a-triangle

There might be different interpretations of "same size triangle", but if you mean area the script there will work well I believe. I hope it helps,

Giulio Piacentino

Permalink Reply by Darren Chang on August 20, 2012 at 2:51pm

Hi Giulio,

Great to hear from the author of Wb. I'm working on something custom-made. But can I ask you another question: if I install Wb on GH first, then install Wb plug-in on Rhino, will that disable the GH's Wb? This just happened to me!

Attached is GH's error message when I load it:

Permalink Reply by Giulio Piacentino on August 20, 2012 at 3:18pm

Actually no that must be a side effect of something else and should not happen... when did you install Wb in Rhino?

were you using a old version of Wb? How did you install it?
and which version of Grasshopper are you using?

Since this is a thread about something else, please feel free to contact me directly via PM.

Giulio Piacentino

Permalink Reply by Darren Chang on August 20, 2012 at 3:28pm

OK, I'll use PM

Permalink Reply by Andrew Heumann on August 20, 2012 at 11:00pm

Ha - I had forgotten entirely about that definition.

Permalink Reply by Giulio Piacentino on August 21, 2012 at 10:28am

Well the currently most popular search engine found it quickly.
It was a nice definition.

Permalink Reply by Andrew Heumann on August 21, 2012 at 12:29pm

Here's how I would do it now. This definition (unlike my older one) works on multiple surfaces at a time.

Attachments:

subdivide_triangle2.gh, 37 KB

Permalink Reply by Darren Chang on August 22, 2012 at 9:09am

Andrew, your code didn't work for me and some batteries are missing... what version of GH do you use and what plug-ins you have?

I have made my own customized version of the triangulation. It first divides the triangular piece along the horizontal direction, sub-divide the horizontal segments, and then connects the dots. This works for my particular project.

Attachments: