Explode planar curve

I have problem about planar curve, I’m trying to explode planar curve to 2 line and 1 arc.
so I use explode but it doesn’t work.
Any ideas about it ? thank you
planar curve.gh (6.9 KB)

This curve cannot be exploded. It’s a degree 3 curve.

An arc through three points on the curved part shows a radius around 50.

Offset the curve inwards by -50 creates a polyline with two segments.

Offset outwards with corner option round results in a polycurve.

If the two segments are rebuilt / simplified before offsetting outwards, the result can be a polycurve built from two lines and an arc.

planar curve.gh (16.3 KB)


Thank you, you save my day.

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I’m curious about how this curve was created?

Here is another way to think about it:

planar curve_2023Aug25a.gh (15.3 KB)


Hi Martin,

I realize the method I posted depends on setting the fillet radius slider by eye… or using your value. So it’s far from ideal. I admire your method of using arc radius to get that curve radius (fillet radius) but am a little puzzled by how you used Offset Curve, though admit it works and is simple.

Still, I wonder if there is a different way to solve this? So far, I haven’t thought of anything better than arc radius to get the essential value at the heart of this problem. This is a geometric construction for getting three points on the arc without picking them manually, but it’s only an elaborate gimmick, not better.

planar curve_2023Aug25b.gh (21.7 KB)

Back to dreamland… :thinking:


Point Group could be used to find the radius…

planar_curve_point_group_radius.gh (15.5 KB)


Thank you too much, I will try my best.

Hah! How bizarre. Still depends on a manual slider value though.

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planar_curve_cp.gh (22.9 KB)

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thanks for spend your time for me.

This one doesn’t rebuild the curve at all, it just splits it at the start and end of the bend: :sunglasses:

planar curve_2023Aug26a.gh (21.8 KB)

It measures the length of Curvature vectors at “analytic” Discontinuity points.

planar curve_2023Aug26a2

Silly stuff. :roll_eyes: Again, I’m curious about how this curve was created?

P.S. Added the white group to construct the desired two lines and one arc from the Shatter result. From what I can tell, they are EXTREMELY close to the original curve.

planar curve_2023Aug26b.gh (26.0 KB)

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