Failure in a section follows shapes

I am having many problems when I tried to have a similar section for different shapes/paths (closed, and opened)
1- I used different definitions for closed and open shapes/paths
2- I cannot have more than one paths in the open shapes (attached screenshot 1A, 1B)
3- I cannot have the same section for the closed paths- I have to have an individual section for each shape. (attached screenshot 2A)
4- Also, for some shapes (closed) I have errors, (attached screenshot 2B)

So, is there any way to have the same section works for all paths? I need to do more than 100 closed and open paths.

Thank you in advance

closed-Open shape.3dm (3.4 MB)
closed-Open (14.9 KB)

Without your code and internalized geometry (or Rhino file), there isn’t much anyone can do.

Dear Joseph for your reply.
And sorry this is my first time to ask a question here. So, how can I upload the file?
Can I attach it here? Or I need to have a new post.


Did you read this page? How to ask effective questions

You can edit your original post and add it there. It’s a good idea to read a forum for a day or two before posting, so you understand the “culture” and norms, eh?

Many thanks

All you had to do was graft the input on your last version and it works for all cases… except for closed ‘Path 4’, which fails for unknown reasons. Not sure I want to spend the time to find out about that one… (11.9 KB) (geometry is internalized, no need for Rhino file)

P.S. For what it’s worth, if you substitute a regular polygon for your star cross section, it will either work or fail on different path curves depending on the radius and number of sides: (14.9 KB)


Many thanks,
Could you please explain why I need to graft the paths? I want to understand the logic behind it.

Many thanks again.

The short answer is because you want to apply the same section curve (star or polygon) to many different rail paths. Beyond that, it’s a complex subject. It becomes intuitive with practice.

Thank you