Evaluate Curve at (t) _ Bug???

The attached file illustrates what I believe to be an incorrect result. All the (t) values are within the curve domain value but for some reason (I say a bug) several of the points do not fall within the curve. Am I missing an essential concept here?

Thanks for any feedback you can offer.

Sincerely,

Stan

Attachments:

evaluate curve parameter bug.gh, 7 KB

Replies to This Discussion

Permalink Reply by Nema Ashjaee on September 3, 2012 at 8:17pm

Hi Stan,

I think you're confusing length with domain. See the attached image. Your curves' domains are actually 0 to 6.855753. You should make sure your "t" values are in that range. Or reparameterize the curves so their domains are 0 to 1 and thus more friendly/predictable.

-Nema

Attachments:

domain.jpg, 280 KB

Permalink Reply by Stan Carroll on September 3, 2012 at 9:13pm

Ahh, I get it now. Thank you for your help, Nema. I am so happy you helped me understand this distinction.

After a little extra research I now understand how the initial curve domains are derived...For straight lines the length equates to domain at the time a line is originally created however, after scaling or modifying the curve control points of the line, the domain does not change from its original range. For spline curves, the domain is initially derived by the length of a polyline defined by the control points of the curve which usually does not equal the spline length. And like the line, the domain of a curve remains unchanged even after scaling or modifying the control points.

Thanks again.

Stan

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