Extracting the vertices of a polyline

Replies to This Discussion

Permalink Reply by nikos tzar on January 23, 2015 at 7:54am

Hi Olivier,

[explode] will return all the vertices and [Curve closest point] will give you the parameter of each point on the polyline (if you want them in a 0 to 1 domain you will have to reparameterize the polyline).

Permalink Reply by Joe Allberry on January 23, 2015 at 7:59am

Alternative without reparameterising (nowhere near as clean, I know...) :

(Graft the geometry input if you're using multiple polylines.)

Permalink Reply by Joe Allberry on January 23, 2015 at 8:10am

Updated GH with inset component to include the first vertex value of 0...

Attachments:

• Polyline Vertex Relative Position.gh, 6 KB

Permalink Reply by Olivier Suire on January 23, 2015 at 8:15am

Hi Joe,

Thanks a bunch !

I suppose that it works because the list of exploded segments is consistent with their location in the polyline.

I didn't know that the "Mass addition" component had this helpful "Partial results output" ; nice .

Cheers,

Permalink Reply by nikos tzar on January 23, 2015 at 8:15am

Just two more things:

1. You can get the same results if you use [discontinuity] and change the L input to "analytic"

2. The t parameter on polylines is a bit strange. The curve's domain is divided in equal parts between control points. That's why you get equal intervals from 0 to 1 no matter where the points are located. This is actually normal behavior but I think it doesn't give you the result you wanted.

If you want an l/L ratio you will have to do this manually:

edit:

just saw Joe's definition which does the same as mine but much faster... so only thing to keep from my post is that (t) is not l/L.