How to remove overlapping lines in grasshopper?

When I "bake" curves generated with different kinds of grids, sometimes depending on grid density or structure, result of baking causes lines to overlap.

Is there possible to remove or unify overlapping lines with grasshopper?

This needs to be done for laser cutting, so laser wont cut same area several times etc.

Replies to This Discussion

Permalink Reply by Daniel Piker on October 31, 2017 at 8:47am

One option would be to use the RemoveDuplicateLines component in Kangaroo2:

It takes as input a list of lines (note that duplicates in separate branches will not be removed, so flatten them first) and a tolerance value. If the ends of a pair of lines are closer than this(with the lines oriented in either direction) it considers them duplicates and removes one.

Permalink Reply by Mikko Leppänen on October 31, 2017 at 9:20am

I'm not experienced with complex instructions or kangaroo. Can you send screenshot containing names with command boxes because I'm not familiar with graphic only interface. Or script itself if possible?

Permalink Reply by Joseph Oster on October 31, 2017 at 9:50am

When I replied earlier, I didn't see the image you posted. Had I seen that, and realized how simple your example is - or had you posted code initially - I would have replied as follows:

Attachments:

overlapping_lines_2017Oct31a.gh, 9 KB

Permalink Reply by Mikko Leppänen on October 31, 2017 at 10:30am

Yes thanks a lot :)

I will study and build that model myself from your example to learn how this is done.

Permalink Reply by Joseph Oster on October 31, 2017 at 11:45am

The tool path will be near optimal if each line is cut from start to end, in sequence. To be more explicit, and even better about that, I added an Anemone loop to identify 25 contiguous segment tool paths for the 93 line segments in my example - all counter-clockwise around each hexagon:

(re-posted; more explicit with three colors instead of two)

Attachments:

overlapping_lines_2017Oct31b.gh, 21 KB

Permalink Reply by Joseph Oster on October 31, 2017 at 12:18pm

Or you can skip Anemone and get the same number of tool paths (if a little more chaotic?) using 'Join' curves alone. This color pattern doesn't differentiate well enough... in some cases adjacent curves are shown with the same color. Adding a 5th color almost fixes it...

Attachments:

overlapping_lines_2017Oct31c.gh, 11 KB

Permalink Reply by Joseph Oster on October 31, 2017 at 12:35pm

Forget about multiple colors, just use this 'Tree/List Viewer' ('list idx' slider) to see each curve. Again, no Anemone, just 'Join' curves.

Attachments:

overlapping_lines_2017Oct31d.gh, 21 KB

Permalink Reply by Mikko Leppänen on October 31, 2017 at 1:39pm

This demands time to investigate and memorize how to build. Is it possible to define "curve" group direction in hexagonal grid, for example "from top to bottom or left to right" and color code them as layer or RGB for laser cutting?

Permalink Reply by Joseph Oster on October 31, 2017 at 2:00pm

memorize how to build

I gave you the code, no need to memorize.

As to sorting and layering, many things are possible. You need to understand data trees and paths, though. For example, you can reverse the output of the 'HexGrid' component and/or the 'tool_paths' list ('Shift' output). The original grid rows and columns are lost, unfortunately, by flattening the 'Item L' input.

Permalink Reply by Joseph Oster on October 31, 2017 at 3:02pm

Reverse list and 'Flip' matrix on the 'HexGrid' output results in left to right, top to bottom "rows":

Attachments:

overlapping_lines_2017Oct31e.gh, 13 KB

Permalink Reply by Joseph Oster on October 31, 2017 at 3:22pm

Sorry for the drip, drip... This is Anemone again, by the way, as the results are more predictable.

Had to define seven colors before getting clear separation between tool paths. Numbers are placed at start points (paths zero and one share the same start point).

Attachments:

overlapping_lines_2017Oct31f.gh, 24 KB

Permalink Reply by Joseph Oster on October 31, 2017 at 3:41pm

Bake the 'Shift tool_paths' output, 'select all' in Rhino, 'Analyze | Direction', and you see these white arrows on the tool paths, starting at each path number.