Getting the intersecting shapes

Grasshopper
#1

Hello

I try to solve this simple problem for nearly a month and cannot find easy solution.

Im trying to extract all the shapes created by intersecting all the lines from any group of curves, create new shapes (eventually do a contour - also fails) and make them separate polygons.

2020-12-02 09_47_04-Rhinoceros 6 Commercial
2020-12-02 09_47_04-Rhinoceros 6 Commercial1747×1235 194 KB

getting subpolygons.gh (18.9 KB)

image
In yellow, what i get,
In cyan/green what i want (for every red line intersection).

I cant use the intersection tools as they are slow and i need at least 3 of them which creates a real mess. I tried other variations but none seem to work :roll_eyes:

Thanks in advance for any hints.

#2

This uses the Geometric Region component from Heteroptera.

Canvas at 04;57;18
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getting subpolygons-b.gh (10.8 KB)

Any polygons you don’t want, you can cull using distance of their centroids from the origin.

1 Like
#3

You can also do this with standard components:

image
image1920×1040 362 KB

Essentially create a surface larger than your shape, split that surface with your rectangles, and get rid of the inner and outer surfaces you don’t want by removing the two largest area surfaces.

getting subpolygons MBH.gh (21.3 KB)

1 Like
#4

Thanks very much Ethan!

Time to exploe Heteroptera (which i already had installed!)

Got it where i wanted it

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image1164×1615 372 KB

#5

I’ve found that the Geometric Region of Heteroptera doesn’t always give good results when curves are involved, but works well for lines, as in this case. Otherwise, I’d use Split Surface as you did.

1 Like
#6

Im testing Split surface but ‘periods of 100%cpu’ happen much more…

but damn it works well (graphic ouput wise - which is the kind of effect i was looking for…)

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image3031×835 614 KB

#7

If your goal is to get offset curves and nurbs curve cells inside of them, then you could also use Clipper plugin.


Canvas at 20;36;34
Canvas at 20;36;341620×602 213 KB
#8

That is exactly it (new component to play with!)… Thanks HS_Kim!

OK, see? i knew there was a simple way… or 20…

Now going to try to make a checkerboard out of that. New challenge.

But i see a new type of solution and testing for intersection. okaaay. New puzzle!