Creating a Mesh Cave/Tunnel From Points

Hello All,

I'm semi-familiar with grasshopper and have a general understanding of lists and data matching, but not a spectacular one.

The attached images show a portion of an .xyz point cloud that was brought into rhino via a python script and then exploded with the intention of creating a mesh surface. The cloud represents the inner surface of an actual natural rock formation/tunnel.

For those interested - https://en.wikipedia.org/wiki/Tonto_Natural_Bridge

I have had other successes with python, .xyz point clouds, and the Delaunay Mesh component, however those were all relatively flat ground situations.

I want to achieve a cave or tunnel with the mesh but when I attempt that, points begin to connect in all directions creating an audacious mesh that'll melt your face off (see attached image 03). I assume this is because GH does not know how the points relate to each other, just that they exist in space.

Does anyone have suggestions on how to get the triangulation mesh to occur ONLY along the tunnel and not across it? Perhaps Delanuay is not correct?

-Thank you for your time,

Danny

Attachments:

Replies to This Discussion

Permalink Reply by Daniel Gault on March 17, 2017 at 11:47am

.txt Data set portion

Attachments:

Data Set Portion.txt, 3 KB

Permalink Reply by ng5 Alex on March 17, 2017 at 12:00pm

yup, it seems there is not any color info.

Permalink Reply by Daniel Gault on April 7, 2017 at 5:58pm

Alex,

An update on my point cloud project...

I was able to get a giant .txt file in the xyzrgb format from our surveyor. The file was....357,257,187 points. This crashed rhino when I attempted to bring it in, obviously. But using the trial version of the text editor EmEditor, I split this 15.5 GB file into 9 even parts of 39,695,242 lines. I brought each of those in under their own file path and Volvox compiled the whole cloud. Crazy. I attached a screen shot of the results. Thank you for pointing me in the right direction on this. Hopefully, this post will help others in the same situation.

-Danny

Attachments:

Full Cloud.PNG, 2 MB

Permalink Reply by ng5 Alex on April 8, 2017 at 4:30am

wow nice landscape. glad it all worked out eventually!

best

alex

Permalink Reply by ng5 Alex on April 8, 2017 at 6:06am

btw i haven't used so big clouds, so i would like to ask whats the ram usage and viewport responsiveness (dynamic option i guess) with 357mil points?

Permalink Reply by Daniel Gault on April 9, 2017 at 3:36pm

There are definitely issues in that area. The RAM on the machine I'm using is 16GB DDR3 1Ghz quad channel. Rhino and the point cloud tie up 98% of that then I imagine it starts borrowing from my hard drive which is a 1 TB, the old 3.5" form factor probably a 7200 RPM.

The viewport takes 1-3 seconds to respond to any movement of the model. I have an ATI Radeon Card but its old, I believe its a 1Ghz Gpu with about a Gig of memory.

So not the ideal machine to work the cloud but its still manageable.

Permalink Reply by ng5 Alex on April 9, 2017 at 3:42pm

i see. well ram is always an issue, but then i think clouds can bring any pc to its limits.

thank you for the info.

cheers

alex