Trim 3D Curve Form with Plane

WhatsApp Image 2023-03-02 at 22.29.58
Hey! I was searching through the Forum and also in the internet and didnt find any solution for this (I’m a beginner). Is there a possibility to trim/delete the part of my geometry that’s under the XY Plane (with Z = 0) ? that the form would be like in the picture with the Box. I will attach the GH file if needed
Delete under XY Plane (internalized).gh (9.2 KB)

Thank you a lot for your time!

Yeah, but you didn’t internalize your geometry.

what do you mean by that? (as I said, I’m a beginner so I’m sorry if I’m asking an obvious question)

Your Crv param is empty. Probably refers to a Rhino file? Right-click on it and choose “Internalize” to save the curve into the GH file.

3. Attach minimal versions of all the relevant files

Or post the Rhino file.

ahh, yeah you’re right, Im sorry I didnt realize that. Thank you for your patience, I will send it with the internalized geometry, which I hope did right!
Delete under XY Plane (internalized).gh (9.2 KB)

Delete under (18.9 KB)

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Thank you so much for your help and your patience sir!! You really helped me a lot!! Have a nice day!

Here are two more ways of doing the same thing, both using PCX (Curve | Plane intersection) instead of Split with Breps. Version ‘b’ treats all the curves as a flat list, like before:

Delete under (25.7 KB)

Version ‘c’ keeps the two lists of curves separated by careful attention to data trees. More useful?

Delete under (32.8 KB)


Another Time thank you so much, now I even know different variations of it so I can make more use of your shared knowledge in future for different scenarios! Small side question since I think you are an expert at Grashopper: what’s the best way to learn Grashopper? Just by Youtube tutorials, or would you recomend another method?

I like to use Trim with Brep also.
I feel there is something simpler to build the trimming box…

Practise, practise, practise :smiley:

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thank you too :))