Feature Requests: Curves

Things that would be nice to see:

Option on FAIR to preserve the orientation of the ends. Currently, if a curve is tangent to other curves at the end, FAIR, makes them untanget.

Option on CURVETHROUGHPT to specify start and end tangent curves.

Option on CURVETHROUGHPT (Interpolated) to specify a tolerance for control point curves such that the curve will be within the tolerance of the control points.


I would love to see some kind of constraints for both curve and surface (Nurbs) editing:
(all with the aim of “designing” curves and surfaces)

  • symmetrie / reflect / radiate
  • constraint G0,G1,G2 to curve end and surface edge (like mentioned above)
  • lock single controll points
  • set maximum and minimum curvature
  • set point where curvatures changes orientation
  • set maximum / minimum / absolut length
  • fix curvature to one side (don t allow s-linke shapes)
  • through point (like mentioned above)
  • constraint CVs to lines or planes (limit amount of movement / freedom)
  • match, matchSrf should respect above constraints
  • overall tolerance for all conditions
  • specific tolerance for single conditions.

for me it looks like most of above can somehow be implemented with kangaroo and a very dense polyline in the background - but i imagine more like a interface that is similar or integrated into sketches. … well soon there is x-mas :wink:

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Is this request is for CurveThroughPt with CurveType=ControlPoint? That option results in a non-rational degree 3 NURBS curve with uniform knots which has control points at the locations of the input points. It is exactly the same curve which results from the Curve command with Degree=3 and SubDFriendly=No with the same locations for the control points.

CurveThroughPt with CurveType=ControlPoint could create a curve close to the input curve if it added knots and control points in between the input point locations. The result would be a curve with more control points and spans.

CurveThroughPt with CurveType=Interpolate results in curve which goes exactly through the input points.

I would also like these options to be implemented.

i had the feeling that this was requested a couple of times already, i found no topic on the quick run, i would also think that fair should preserve the orientation…

assuming smooth works similar which you can use on single cp´s you could simply avoid the cp´s responsible for the orientation/tangency and use smooth instead.

RH-72060 Fair: keep end tangents / curvature option

as for your other wishes on CurveThroughPt, I’d like to see an example where this would be useful and how you would use it to better understand.

Attached is an example. The points are rounded to the nearest 1/16" in X/Y/Z. The should then be within 1/32" the location of the original curve. However, there can be errors.

Problem Curve.3dm.zip (39.2 KB)

I have drawn a curve using control points and done selvolumepipe 1/32. For most of the section things are good. However, they are way off at the sharp curves at the bow, stern, and where the hull widens at the center of image.

It would be desirable to create a curve within a specified distance of all the points.

To my list I can add fairing of surfaces. Something like the smooth command that works within a specified distance.

RH-72060 is fixed in the latest WIP

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wow… that was swift!