Feature Request: Curve Through Interpolated Points

If I have:

  1. Two curves that are not connected.
  2. A set of points located between the two curves with one point located the end of each curve

And I Curve Through Interpolated Points to join the curve through the points and while specifying Start or End Tangent, I wish Rhino would ignore the point at the end for the purpose of the tangent.

It is hit or miss whether Rhino locks on to the point (meaningless result) or the end of the curve.

Hi -

That seems to behave as expected here in a quick test - or I am completely misunderstanding the issue here. Can you post a simple file?

An illustration:

  1. I start with two lines and three points. Two of the points are at the end of a line.
  2. I copy and delete the two points at the end of the line.
  3. I draw a curve through interpolated points using the start and end tangents on both.

If there is no point at the end of the line, I consistently get the curve tangent to the line.

If there is a point at the of the line, I more often than not get a curve that is not tangent to the line. It appears that the N/T opens lock on the to the point, rather than the line.

Problem Curve.zip (7.7 KB)

Hi -

I’m not sure how you are getting that non-tangent curve. This is what I do:
2021-06-02 Tangent InterpCrv


Is this the difference between InterpCrv with Knots=Uniform vs Knots=Chord?
I am assuming InterpCrv in Rhino for Mac has the same options as in Rhino for Windows

1 Like

Hi David -

It doesn’t look like that in this case, no. With either of those, the resulting curve is tangent to the lines.

No, Both are with knots=chord.

The issue is the T/N options (tangents) that seem to lock on to the point rather than the line (or any other type of curve).

Sometimes, the curve will turn out tangent to the line but it is random.

For curves that are not lines, you’ll either need to turn the points of that curve on or have construction geometry. You need to place the tangent point in the correct direction.

If I don’t have a point at the end of the start/end curve, with the T/N option I get tangent indicator that is fixed along the tanget.

If I have a point at the end of the line, the tangent indicator will move in any direction (most of the time).

My observation is that sometimes tangent locks on to the end of the line (correct result) and sometimes locks on to the point (the tangent line can go anywhere).