How to make a line have control points to match a straight curve?

Rhino Rhino for Windows
1

Hi
V5
I need to explain this one !
I have a curve which started out slightly convex, with control points, and after curvature graph tweaking , its almost straight.

It has 10 points, one at either end obviously, one the result of starting tangent, the rest from InterpCrv clicks to a halfcosine template (as per skyg aerofoil method)

If I draw a line same length as this curve and need the same number of control points, firstly I make it degree 3, then I use Insert control points command and click where I see control points on the aforementioned curve (ignoring the tangent one) intersecting with the halfcosine template . I end up with more !

How can I get the same number of control points distributed as I see on the aerofoil section ?

HalfCosine point spacing straight line.3dm (38.9 KB)

Steve

2

The command “Rebuild” will allow you to rebuild a curve with the desired number of points. It just spaces them out as it will though, it doesn’t allow you to select where they go.

3

Hi Steve, if you run the dashed version of the -_Rebuild command then you’ll get an option _SelectMasterCurve. Then the rebuilt curve will have the same structure as the master curve.

HTH, Jess

2 Likes
4

Copy your original curve, then use SetPt on your copy (Set y) to make it flat with the identical parameterization.

5

Hey Jess, I never knew this option. Cool! thanks!

gr, Tobias

1 Like
6

Hi,
Jess thats exactly what I just needed for a curved aerofoil curve :slight_smile:

I wonder why Rebuild has a - version, when doing aerofoil curves having the same cosine or half cosine spacing is important and that is TIP OF THE WEEK IF NOT YEAR !

skyg thanks for that method for the straight curves, aerofoil port side sorted :smile:

Steve

7

That is such a top tip!

Thank you!!