how to get t value of a curve at a certain point

Hi everybody!

I'm currently doing some GH and VB engines for a design studio at university. I managed quite quickly to get a point on a OnCurve defined by a certain t-value using crv.PointAt(t).
Now i would need the t-value of a certain point on the curve - so exactly the other way around. Is there a way to do that? And i yes, how? Something like crv.TAt(point) - I knwo that that expression doesn't exist but just to illustrate what I'm looking for.

A second question concerning t-values on a curve is following: using a evaluate curve component in GH allows to reparametrize the input curves so that the t-value of the starting point is always 0 and the one of the endpoint 1. Is there a way to do that in VB as well? So far I always got t-values which go up to quite high numbers...

I would really apreciate your help!
Martin

Replies to This Discussion

Permalink Reply by Vicente Soler on April 30, 2010 at 5:45pm

Try something like this:

Dim t As Double

crv.GetClosestPoint(pt, t)

a = crv.Domain.NormalizedParameterAt(t)

Edit: There's also crv.Domain(0,1) on 0.7 ~~but i can't make it work~~ it works.
On 0.6 try crv.SetDomain(0,1)

Permalink Reply by Vicente Soler on April 30, 2010 at 6:04pm

I forgot to change it, it's:
crv.Domain = New interval(0, 1)

Permalink Reply by Martin Wyss on May 1, 2010 at 2:36am

Thanks so much for your very quick help!!
Both worked very well in GH 0.6.0059! I'll try afterwords to install and use the new GH-version but I'm somehow afraid, that my other scripts won't work anymore... But as David Rutten mentiones the "old" version will be still available for a while.

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