OpenSCAD is all triangles and vertices. Fillets are difficult to do. Outputting circles/spheres generally requires you to for-loop over vertices a lot.

Libraries like build123d and cadquery use OpenCASCADE, a boundary representation kernel. You think in terms of the enclosed solid and perform operations - boolean add/subtract, fillet/chamfer, stamp text, etc - that return a new solid.

▲

7bees 2 hours ago | parent [-]

I'm not sure I understand your comment; OpenSCAD has functions like sphere(), cylinder(), etc. Most OpenSCAD models I have seen are built up primarily from solid primitives combined using boolean operations, just as you describe for the other tools.

https://en.wikibooks.org/w/index.php?title=OpenSCAD_User_Man...

	▲	seltzered_ an hour ago \| parent \| next [-]
		Theres a better description of the differences here: https://build123d.readthedocs.io/en/latest/OpenSCAD.html#tra... Some of the differences may be in when you are trying to reference a face/edge to build off of, not just about the primitive function being used.
	▲	Doxin an hour ago \| parent \| prev [-]
		OpenSCAD works natively with triangle meshes. sphere() will create a spherical triangle mesh. These libraries on the other hand can natively represent a sphere for instance. This means that during CAD-ing you don't need to worry about resolution, that's a consideration for export only.