Shortest Walk Across Planar Surface

Hello everybody,

Im currently trying to find the shortest walk/path along a surface to the center of polygons adjacent to this planar surface.

I am aware the shortest walk component uses a network of curves to work, but I got nothing like that in this option. Just a starting point, where to go, and along where to move.

I dont know.... is it even possible?

Im uploading the internalized geometry if anyone is willing to try.

Thanks for any ideas.

Shynn

Edit: Doing some digging I found this thread about extracting the axial curve of a 3D mesh: http://www.grasshopper3d.com/forum/topics/code-to-extract-center-cu...

Obviously this is much less complex as its just a planar surface. Hopefully this will illustrate better what Im trying to do.

Attachments:

Geometry2.gh, 144 KB

Replies to This Discussion

Permalink Reply by peter fotiadis on April 11, 2017 at 11:57pm

Well ... as Anders pointed already actually you want a straight skeleton solution (Google that: very few code resources are around including a Java one that "works" [holes and the likes]).

That said that well known classic paper attached describes an algorithm that ... er ... works "when it works". Therefore the C++ upon request ... well ...

Unfortunately I'm not willing to share my C# on that matter.

Other than that routing using accurate and real-time fast medial/straight stuff is indeed critical in too many design areas (nothing to do with roofs and the likes) but not in ones related with walks in urban layouts. For instance imagine optimum infrastructure solutions where the cost per m is much much higher than one could imagine.

Attachments:

Straight Skeletons Implementation.pdf, 246 KB

Permalink Reply by peter fotiadis on April 12, 2017 at 3:13am

BTW: A straight skeleton is not "exactly" a Medial axis thingy (but who cares?)

Permalink Reply by ShynnSup on April 16, 2017 at 12:45pm

Peter, I am afraid the "Line to Path" script returns an error when trying to use certain geometry. I replicated the error with a much simpler geometry. I cant figure out why its failing....

The geometry is internalized.

Attachments:

Lines_to_path_V1B Error.gh, 22 KB

Permalink Reply by peter fotiadis on April 17, 2017 at 1:00am

Have I've mentioned that I hate computers like my sins? (lot's).

Added a new variable that is part of the arsenal of strategies as found in the (never finished: extreme boredom + zzzzzzzzzzz) 1C update that solves intersection events (path crosses neighbor building > try the next best > ...).

Mighty(?) 1C (voted by Code Project as the top C# of the previous century) could(?) answer(?) all the questions and works(????) as follows: blah, blah ... then ... blah, blah ... and if this ... blah, blah ... then that ... blah, blah, zzzzzzzzzzzz.

Attachments:

Lines_to_path_V1B_NoError.gh, 126 KB

Permalink Reply by ShynnSup on April 12, 2017 at 11:50am

Thats totally fine Peter, I will see what I can find in order to create a better curve network, or maybe even result to draw it by hand or end up using the median axis you provided.

But a side form that, could you upload the final needed code for making the connections between the centroids of the boxes and the paths, without these connections intersecting across the boxes? That is all Im really missing right now, those connections.