Trimmed Surface problem

I have a simple trimmed surface from a subd and need to make a space truss structure ignoring the trimmed areas, I have already shrunk the edges but GH is still populating the panels when I use Lunchbox onto the trimmed areas.

Does anyone know how to solve this issue or guide to find a answer?

Initial SubD with the trimming shapes

Final trimmed surface

Surface with the space truss structure

Thank you in advance!

Trimmed Suface (31.2 KB)

Hey @mauriciovb - no matter how simple, clean, and beautiful your trimmed shape is it’s still trimmed and lunchbox wants untrimmed so you’ll continue to get the truss system drawn on what it considers the untrimmed surface - your situation calls for something more involved and not something a plug-in will give you - something exists out there I assume, most likely via code - I notice you were tri-remeshing your shape, does this mean you’d also consider doing a space frame using the mesh triangles?

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there are multiple topics on this f.e.

but as far is i know you have to find a method to remodel your geometry as a clean surface.
This would be my attempt:

Trimmed Suface (37.8 KB)

Unfortunatly i could not finish it but maybe some oneelse will take over but you could sweep the outer edge naked edges with the plane brep intersection as rail (blue) or creat a ruled surface, loft whatever from the brep intersections (green). the problematic part marked red . hopefully someone has a good idea how to solve it


this probably is not working with the space truss because it would creat multiple surfaces anyways maybe this triggers ideas for working solutions

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That’s very easy via code. Notify if you want an entry Level C# on that.

But trusses without clash detection (sleeves, nuts, bolts, tubes etc etc) is a 100% nothing thing (that is done via VV, VE, EV connectivity and using solely trigonometry). Anyway a truss without connectivity is 10000% useless in real-life.

That said a W truss (say a MERO) with quad nodes in top/bottom requires a planarity check (i.e. checking min dist between diagonals VS some rational value) … if the related envelope follows the quads (i.e. is not done via triangular modules). Plus there’s the structure rigitify little thing.

Plus if the “realistic” members (i.e. going from abstract axis to Breps + some detail) are many … one should use Instance Definitions otherwise … well … you can imagine what would happen.

In general have in mind that solving a real-life truss that follows some non planar Surface/BrepFace (or some “equivalent” Mesh) is impossible without code.