Edit Curve drawn with InterpolatePoint and keep curve thru points..how?

Rhino Rhino for Windows
1

Hi,
I need to alter the shape of a 2D curve drawn with Interpolate Curve tool through points which are in fact at the ends of dimensions for an aerofoil section.
It all looks fine except for a bit of a bulge between two points, or sometimes one might have a flat spot and I need to flatten the bulge or pull out the flatspot BUT THE CURVE MUST STILL GO THROUGH THE POINTS EITHER SIDE OF THE OFFENDING AREA.
If I turn on control points I get the control point in that region BUT moving it also sees the curve depart the points its been drawn through and it must go through those points in this example.

How does one edit a curve drawn with InterpolatePoints where the whole concept is that it needs to folow those points.

I thought add a point to the curve and then moving that point will see curve follow it and all the other points, but one can move any of the points and the curve doesnt follow.

Its all about getting a correct looking curve that adheres to the points which are at the ends of dimensions and the curve must go through them !

I find Knot:chord gives the best curve .

What is the best way of adjusting the curve as such. Methinks add another point then as I move the point the curve will follow.
Any other ways to alter the slight bulge and have the curve still run through the points ?

I can see that its possible and still have a good flowing curve through the points.

I use a tool in Photomodeler and one can add a point to a curve and fine tune the curve and it still runs through the points either side of that addition.

Steve

1 Like
2

(probably not the best way but…)

• select all the points you currently have and place them on a separate layer
• add _Points to the curve in parts you’d like to edit
• delete curve
• turn on History modeling
• run _CrvThroughPt on all the points (or _InterpCrv)
• lock the layer containing the original points (the ones that can’t move) as prevention against accidentally moving those ones.
• move the other, new points as you see fit… maybe using nudge instead of the mouse.

3

You might try this:

Split the original curve at the points where you don’t want it to change.

Edit the portion between as you need, trying to keep the ends matched up to the originals reasonably closely. You might need to add some points to the portion being edited.

Then use Match to match the edited portion to the originals with curvature continuity, preserve opposite end (also curvature continuity) and Merge checked. You need to do that twice, once for each end.

–Mitch