Overlapping Lines

Hey Everybody,

I was wondering if anyone has any suggestions on how to resolve an issue I am having. I had used a grid, and, based on the width and height of each cell, I created grids nested within the grid. This has more or less created a highly subdivided grid (much like this http://www.pyser-sgi.com/images/thumbnails/Graticules/NE29%20med.jpg)

My issue now is that I have to begin fabricating this grid. In order to do that, I need to cull the lines which overlap. Usually, I could just Kangaroo or test for the curves' midpoints, but, because the curves are of different lengths at times, I need purely to detect overlaps. I have tried a bit with Python, but I was unable to get it to compare each line against every other line.

Thanks very much for any help possible,

Connor

Replies to This Discussion

Permalink Reply by Danny Boyes on June 3, 2013 at 11:07am

Do the lines share starting points? Or can a line be overlapped part way along another curve?

Permalink Reply by Connor Gravelle on June 3, 2013 at 11:12am

The latter case. Unfortunately, the lines sometimes overlap without actually having coincident start or end points.

Permalink Reply by Danny Boyes on June 3, 2013 at 12:05pm

If you are after a single line representing a grid "column" or "row" then here's something you might find useful.

What I've done is to extend every curve beyond a boundary:

(Red Dots are end points of multiple curves in a grid system)

Find their intersect points and classify them.

So that you can end up with all similar curves on a single branch:

then you can find the Start and End point withing the grid system of that line and create a single representation.

Attachments:

OverlappingGridsCurves.gh, 26 KB

Permalink Reply by Danny Boyes on June 3, 2013 at 1:17pm

3D version

Permalink Reply by Danny Boyes on June 3, 2013 at 3:12pm

Here's a better one using a sphere as the bounding volume

Attachments:

OverlappingGridsCurves_3D.gh, 19 KB

Permalink Reply by Connor Gravelle on June 4, 2013 at 10:02am

Okay thanks so much. These were very helpful. I'll dig through their logic more deeply moving foward. Again, thank you very much. I really appreciate it.

Permalink Reply by Marios Tsiliakos on June 3, 2013 at 11:15am

If your grids are like in the schema provided and you have been using the square grid component per se, you can cull "naked"(surrounding cells surrounding edges) from the second level of grids and after, then explode everything and apply a duplicate detection script either on Kangaroo or in python ect.

best,

Permalink Reply by Connor Gravelle on June 3, 2013 at 12:51pm

Thanks, this is a viable option, but the thing is a three-dimensional grid. Thus, always removing the outer most edges will result in loosing some of the edges which do not intersect with the nondivided areas.

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