If I know the distances between a point and two space curve, how can I locate this point? is this point unique?

Hello everyone,

Here is the question. I have two space curves, and I want to find a point (location), with the known distance to the two curves. As the pic shows, the distances of the point to the short and long curve are 1.9 and 2 mm. Is this point unique? And How can I find this point (location)?

My idea is like this:
1, create perpendicular plane for each curve, then draw circle with the radius as the distance;
2, move the perpendicular planes (circles) along the curves until they have tangency.
I may do it manually, however, I don’t know how to realize it automaticaly.

The curves are here: spacecurves.3dm (29.2 KB)

Any suggestion and comments are so appreicated!

You can make a pipe with radius equal to your distance for both curves, and then intersect the 2 pipe surfaces.
In the picture, any point int the yellow curve is a valid result.
So, no, there is not an “unique” solution.
You might need to add another “rule” to the problem.


Thank you, Riccardo, for your quick and nice answer!

You method is much better than mine. So I could change the question, how can I find the first point (from bottom to up)?

How accurate does it need to be?
You could divide the intersection curve and then sort for the Z key. (But you might be off by a small factor. That’s why I’m asking.)

Or maybe there is even a much easier solution, but I can’t think of one right now. :sweat_smile:

1 Like

Thank you, Luc, for your suggestion. Yes, I think that’s a good idea. I don’t need very accurate location.

Thank you all!

lowest intersection.gh (7.8 KB)


That’s great, Riccardo!!

Thank you so much for your help and patience!

:clap: There is the easier solution …
Nicely done : )