Parameterization Error

I'm attempting to define a pipe sleeve using a point and curve as input geometry.

To extract the curve segment I'd like to pipe, I'm dividing my desired offset value over the curve length then adding that value to the parameter of the input point. However my result is not accurate- the resulting sleeve is an inch or so short. Why is this?

Notes: the model space is in feet (I'm sharing this file within my office) so I am constantly using division components to convert my values to inches. I'm very open to any suggestions to improve any aspect of my approach.

Attachments:

HEINZLER_pipe.3dm, 301 KB
heinzler_pipe.gh, 17 KB

Replies to This Discussion

Permalink Reply by Hyungsoo Kim on August 1, 2016 at 4:31pm

Hi.

This could be one way.

Attachments:

heinzler_pipe_re.gh, 25 KB

Permalink Reply by Joseph Oster on August 1, 2016 at 6:43pm

Yes, 'Eval (Evaluate Length)' gets you the same result I got with 'Divide Length'', and more directly. I forget about this one... thanks.

Permalink Reply by Matt Heinzler on August 1, 2016 at 8:48pm

outstanding. thank you! learning a lot from your help

Permalink Reply by Joseph Oster on August 1, 2016 at 5:40pm

't' doesn't correspond directly to linear length - mysterious but well documented.

Based on some code I did recently: Dividing a curve using a base point...

http://www.grasshopper3d.com/forum/topics/dividing-a-curve-using-a-...

I came up with the attached that splits your curve at your 'MID POINT', then divides each curve by half your 'SLEEVE LENGTH', gets the first point on each sub-curve and the corresponding 'CurveCP' and 't' value on the original curve.

What I never understood about your example is the difference between your 'SLEEVE LENGTH' slider of 24 and your part length of only 1.874?

Attachments: