Torsion of a Space Curve

Replies to This Discussion

Permalink Reply by Shawn Fernandez on December 2, 2010 at 11:47am

Anyone?

Permalink Reply by David Rutten on December 2, 2010 at 3:27pm

Looking into it...

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David Rutten
david@mcneel.com
Seattle, WA

Permalink Reply by David Rutten on December 2, 2010 at 4:41pm

Seems that in order to compute the torsion, you need the first, second and third derivative of the curve. There's no way to get these in RhinoCommon at the moment. I just added some overloads to the Curve.DerivativeAt() method so that you can specify the number of derivatives you want, but this won't be available in Rhino5 until the next wip, and it won't be available in Rhino4 until the next Grasshopper release.

In the meantime, you could try to approximate the torsion by sampling the curve around the parameter you're interested in, then try to come up with a decent value.

Out of curiosity, what are you trying to accomplish?

--
David Rutten
david@mcneel.com
Seattle, WA

Permalink Reply by Shawn Fernandez on December 3, 2010 at 7:36am

It is part of a formula I am using to construct developable line generators from the curve in R2 and R3 simultaneously.