Line tangent two curve fail there a curve limit?


can one have too shallow a curve ?
I have two curves which dont quite overlap and I need a line tangent to two curves to bridge the gap.

However despite both being proj to cplane, a curve doesnt form after the line tan to two curve command.

why ?

file attached.Line tangent two shallow curve fail.3dm (26.2 KB)

what else could I use ? blend maybe. Does blend use tan lines ?


(Chris Kuether ) #2

Steve, your two curves actually intersect.


Ah, so it wont bridge the slightly dipped area then, I need to chop them, i.e. it wont bridge a river if there is a bridge already there !

ok snipped the middle out, still no joy.

Line tangent two shallow curve fail.3dm (29.8 KB)

Tried blend but it simply puts a curve between the blunt ends, if these were arcing just a bit more and I wanted to keep the arcing flavour as opposed to sticking in a straight line, what command would create an arc in keeping with the existing arcs starting and ending tangent, i.e. feathering into the arcs just nice at the point where a tangent line would start and end , or thereabouts ?


(Margaret Becker) #4

Since your curves “dip” down toward each other like the top of a heart shape, there is no solution that will give you an arch shape between them that is tangent at the ends.

I suggest that you turn on the control points and the CurvatureGraph for both curves and start drawing a new curve, snapping to a few key control points of the old curves. Start the curves way back before they start to dip, skip the control points near the ends and then pick up the control points on the other side. Skip snapping to control points where the curvature graph dips and the control points near the ends of the existing curves.

Split the old curves at the ends of the new curve and join.

(Pascal Golay) #5

As far as I can see there is no straight line that is tangent to both curves.