Rotate curve perpendicular to other curve

(Sorry, I hope I'm not spamming the forum. I do find it really useful to check other topics though, so maybe other people might me interested in an answer to my question as well... )

I'm trying to sweep a profile along a curve (first I rotated it so it was vertical). I was able to move it to both endpoints. Now I'm wondering how I can rotate is so that it's perpendicular to the curve (both at start and endpoint). (Like the green line that I drew in Rhino...)

I've been trying to extract vectors from the endpoints, make them tangent, but I have not been albe to match anything to a rotate function.

Any ideas?

Replies to This Discussion

Permalink Reply by Anja on December 9, 2010 at 9:05am

Bit bigger:

Permalink Reply by Danny Boyes on December 9, 2010 at 9:39am

Hi Anja,

Sorry I'm not answering your question directly as I don't think its the right question. Really the question should be "how do I make something perpendicular to a curve?"

There are a couple of components that facilitate this: Perp Frame creates a Perpendicular Plane at a given parameter on a curve. And Orient allows you to change the basis of geometry from one Plane to another.

Here I have drawn my section Curve in the XY world Plane with my curve based at the origin and then oriented it to the perpendicular planes at the start and end of the rail curve. I have included the rotate plane about the Z axis in case the solution was not as expected, you can manually alter it or try flipping the curve.

Permalink Reply by Anja on December 9, 2010 at 10:12am

Wow Danny, thanks for the super fast reaction.

I have tried to use your definition (took me a while to find everything, since I normally work with text instead of icons).

I can't figure out why the end result is split in three parts? The railcurve is not?