Extract Boundary of Grading Object

[Anonymous]

I like the 'Extract" feature for surfaces, where I get get the contours or boundary of a surface in PL form without having to explode the surface. I have not figured out how I can do that same thing for grading objects. So far I have been exploding grading objects and then remaking them. Seems cumbersome...is there a command somehwere I'm missing?

[miked]

If I am understanding you correctly you want the boundary where a grading meets a surface or similar.

There is no way to extract the boundray as far as I know. But a work around would be to use the offset comand and offset the boundary feature line 1 unit and then offset that feature line back again and delete the 1 unit offset line.

[sboon]

If you create a surface from the Grading group then you can display and extract the boundary of that instead.

[Anonymous]

Thank you for the replies, some good ideas although I think the next release of C3D should just have a button that does it since I'm doing this task repeatedly all the time. 

[sboon]

I have posted to another thread the method for extracting a featureline from a grading object - by moving it to another site.  I am curious though about why you need to extract these lines.  Are you using them for another grading or some other reason?

[Anonymous]

Often I am creating surfaces which need to tie into existing grade, and so when I make the boundary of these surfaces, it is a conglomeration grading object daylight lines. If I don't specify a boundary, the surface will triangulate outside of the grading object feature lines in concave areas. So, te easy fix for me is to make one great big boundary. Also, I will never use 3d objects as surface boundaries, as that will usually crash my computer.

[Sinc · Accepted solution]

If you do this all the time, then you may want to look at third-party support, where you can not only extract the boundary, but also prune it at the same time, so you don't end up with tons of unnecessary PIs in the resulting polyline:

http://www.quuxsoft.com/SincpacC3D_Help/SP_Extract2D.htm

[Anonymous]

This looks really helpful. Thanks!

[codee]

Try "lineworkshrinkwrap" command on the Grading Object.