How to get Diameter of circular curve section

Hello to all,

I am not really much into grasshopper and i studied some “Grasshoper/Section/Contour” Tutorials so far. But I was not able to find a solution for my (oviously?) simple question.

The picture below shows my Setup.
I want to have a List of the Diameters of each section. The Modell is a revolved surface and as shown in the Text panel, all contour lines are circles. So showing the diameters in der Text Panel would be perfect.

But how to extract the diameter of each contour section? I tried with deconstruct arc allready and it only works with proper circles, so i might convert the contour output in any kind?

Thank you

You can use bounding box and then box deconstruct?
Or check the curve length and use mathematics to calculate the diameter.

use deconstruct arc .
btw, by saying you are not so into GH, don’t expect to get much help around here… :joy: :joy: :joy:

Is that what you mean with not getting much help? :stuck_out_tongue:


Thank you!
Yes, correct, I used deconstruct arc before :wink: But it might work as soon as i have the circular curve converted somehow…
@siemen : I check the bounding box right now, therefore I would need a bounding box for each section right? I check it out, not to sure how to assign the bounding Box for each separately, but I have a try.


Works Fine here… The reason Deconstruct arc goes red is because you have a line in your list.

You can use the contains logic in the code to remove this if you need to or just leave it out and it will just give you nulls for the non circular curves.


Thank you Matt!
Looks like it is working now, strange, but it even works if I bypass your contains logic afterwards ! So there was some additional magic with your reply. :slight_smile:


With Matts answer I found my mistake now. And yes, It’s a basic I believe :roll_eyes:!

Before I connected the Text Panel inbetween Contour and DArc:

And that’s the fault, It should be not inline with Contour and DArc and works fine for me now.

Thank you for your help and time.