[flowerbreeze]

Do you mean that OpenScad performs boolean/other operations on triangle meshes, but these libraries don't until output? So they might instead use curved surfaces/edges etc as outputs for operations and only convert to triangles for output or export at the very end?

[Karliss]

It isn't even necessary to create triangle meshes during export. You can export as step files. It is a commonly used brep based file format supported by almost any "proper" CAD software. Triangle mesh based modelers can't easily export good step files because they don't operate at that level of abstraction.

[rowanG077]

In professional CAD systems, geometry is not stored as triangle meshes but as mathematically defined surfaces (such as parametric and NURBS surfaces). Triangle meshes are only generated as approximations for rendering. This is analogous to vector graphics (SVG/EPS) versus raster images (PNG/JPG).

Any serious manufacturing will work require a STEP (or something equivalent) which stores these parametric surfaces rather than a mesh.

[Doxin]

yes, exactly.