batch

i am new to grasshopper and studying alone, i created a volume of closed curves from their controlpoints of many polylines(voronoi 3d structure) in space.and the polylines share the same edges. now i have a problem to isolate every single curve with its polyline and then creat a line between the midpoint on every edge of polyline and its closest point on the curve.if not isolate every single curve and its polyline, grasshopper would find the closest point on curves for one polyline. anyone could tell me how to resolve pls?

many thanks in advance,

yewei

Replies to This Discussion

Permalink Reply by David Rutten on September 19, 2009 at 1:58pm

The solution to this depends highly on how your data set is structured. I can't say I fully understand the problem (an image would be nice). It may turn out to be impossible with a conventional node-based approach.

Permalink Reply by yewei on September 22, 2009 at 3:24am

hi david, i uploaded all the materials, would you pls take a look? many thanks!

Permalink Reply by Jon Mirtschin on September 20, 2009 at 1:24pm

As David said, some diagrams or images might help with others to advise on how to address the problem.

I encountered a similar problem when for my rhino plug-in blog tutorial on creating (as best I can gather) the Beijing Watercube (http://geometrygym.blogspot.com ). To create the cell structure, I intersect the Weaire Phelan packing polygons with the target building polysurface. If I created every face of each polygon, each adjacent polygon would share a face with the adjacent polygon and a duplicate curve (one for each face) would be created. Rather than try to post-process out the duplicates, I took the approach to ensure I arranged the polygons could be created with no shared faces. This might not be easy in your situation (I haven't tried the voronoi generator in Grasshopper if that's what your using). There are methods for removing duplicates. If you can post more details on what you're doing, I'm sure you'll get more advice from within the group.

Cheers,

Jon

Permalink Reply by yewei on September 21, 2009 at 3:16am

thanks to both you two.

now i uploaded the original file named as xvoronoi skin, and one other file with fewer polyline named the closest point and the grasshopper

Attachments:

the closest point on the curve .jpg, 128 KB
xvoronoiskin.3dm, 13.9 MB
prova di closestpoint2.3dm, 10.5 MB

Permalink Reply by yewei on September 21, 2009 at 3:19am

i am sorry that i didn't upload anything in time cos i didnt write that question on my computer and i didnt have anything at hand.

Attachments:

pointclosest.ghx, 162 KB

Permalink Reply by yewei on September 21, 2009 at 3:30am

if i choose one polyline and polyline based closed curve. i will get the closest point on the curve of the midpoint of polyline. but if i choose more than 2 polyline and their curves together, i won't get anymore the right points cos grasshopper found the closest point on one curve of the midpoint of another polyline.even not adjacent! so i thought it should be one way to isolate every single polyline and its curve to find all the closest point and batch the same action to all the polylines and their curves. or there esist some better solution, i hope my poor english could make me understood also....i apprecciate any suggestion and help cos i was self struggling with this problem since 2 weeks and didn't make any pass ahead....

thanks in advance,

wei

Permalink Reply by Jon Mirtschin on September 24, 2009 at 2:43pm

Hi Wei,

Sorry, I've hardly had a minute to take another look at this yet, I'll try and do so in the next day or two. I had a quick look, I think from the way you set this up it probably needs to match the tree branch with associated stream so you don't get the mid points of all curves. I didn't get it to work quickly, I'll post back if I have success when I get a chance to look closer.

Cheers,

Jon

Permalink Reply by yewei on September 25, 2009 at 4:31pm

thanks jon, thanks indeed for your answer which gave me quite hope!
i used the pointset reconstruction plugin of rhino to get the 3d volume, then duplicated all the borders' curves for the basic curve params which is the uploaded file, then applied the grasshopper file. wondering that in grasshopper, there esists one possiblity of the loop, all the curves are the variant of the whole body and every curve is local variant to fix the midpoint...

looking forward to your news,

regards,

wei

Permalink Reply by Jon Mirtschin on September 28, 2009 at 3:12am

Hi Yewei,

This is a bit trickier than I'd anticipated. I trialled trees, branches etc to try and merge your streams (or align them) with no luck.

So I've attached an alternate solution, where instead of using native Grasshopper components I've added a couple of vb.net components to achieve the operations. With flattened data streams using short list corelation, seems to achieve you first goal. Take a look and see if it helps you progress.

Cheers,

Jon

Attachments:

pointclosest jm.ghx, 238 KB

Permalink Reply by yewei on October 22, 2009 at 8:03am

hi jon!!! thank you so much!!

i didn't get this ultimate risponse in my mailbox, kept looking forward there to your answer,considering that you are quite busy.... since i just finished my exams of interior and restoration,came here again and found you have answered me one month far...
how eager to try your solution, but why i couldn't download it? could you kindly reupload it?? hoping that you keep that file and can find it!

many thanks again!

wei

Permalink Reply by yewei on October 22, 2009 at 8:28am

hi jon,
grasshpper gave me one archiving message of its event log as below, and nothing else...., the work panel of grasshopper is empty... do you know why?:( many thanks!!

This document contains the messages that were recorded during the most recent Grasshopper file read/write. Whenever a read/write operation fails or behaves unexpectedly, this summary will be compiled and put on display. If you experience problems saving or opening files, please include this log with any bug-report you file. You can use the Send... button to mail this report directly, or you can save the log and attach it to a personal email message. This log contains no personal information beyond what you supply, nor any other information that is not directly related to Grasshopper™.

Permalink Reply by Jon Mirtschin on October 22, 2009 at 2:45pm

Hi Yewei,

Strange, I see what you mean. It's like an empty file.
It's not on my laptop, so I'll check the file tomorrow at work. If my copy is empty too, I'll rewrite it quickly for you. I might try a non-vb net comoponent, I've read a bit more about trees and branches.

Cheers,

Jon