Detecting drawing elements by shape

Rhino Developer
,
1

Hi everyone,

I’m working on a project where I need to convert 2D ship structural drawings (imported as lines and polylines) into a 3D model in Rhino. To automate this process, I’m looking for ways to detect and categorize drawing elements based on their shape (for example, identifying frames, hull sections, bulkheads, and stiffeners).

My main goals are:

  • Identify specific 2D elements by their geometric characteristics (e.g., closed polylines for bulkheads, curves for hull sections).
  • Apply different transformation rules depending on the type of element (lofting for hull sections, extruding profiles for bulkheads, etc.).
  • Automate the entire workflow for faster processing of complex 2D drawings into accurate 3D models.

Has anyone in the community worked on something similar? If so, I’d love to hear how you approached it and whether you used C#, RhinoScript, Python, Grasshopper, or any other method for detecting and classifying shapes in Rhino.

I’m open to suggestions on the best practices or tools/plugins that could assist with this task. Any code examples or references would be really helpful as well!

Thanks in advance for any tips or guidance!

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2

Hey,

Sounds like a fun project

yeah I’ve written software like this.
I used C# in order to get the fine grained control over the geometry tests we needed to run.

I had good fun writing a Curve to Text Converter detector.

We also wrote a Notch detector which is used in sail making.

I really enjoyed the challenge of writing the detectors. Text detection ran to about 750 lines of C#. Notch detectors were shorter as they are simpler.

Generally its fairly quick to get the general case working but the edge cases can take days to get working correctly - and as soon as you release the customer will find another edge case :wink: