Does FreeCAD support non-manifold modelling?

[bkane10]

Hey,

Currently starting to write a thesis comparing manifold and non-manifold modelling and which to inquire, does FreeCAD support non-manifold modelling?

All the best

[shoogen]

If you work mainly in python and not with the GUI you might be able to some useful things with non-mainfold geometry.
But most of the tools in the GUI are meant to work on solids. (which, by definition, need to be mainfold).
I would say: Though FreeCAD might be useful in come cases, non-mainfold modelling is out of it's focus, and is clearly not supported.
A typical example is out sketcher. New users sometimes create non-mainfold sketches. But those can not be extruded (or padded) to a solid by our geometric modeling kernel. The result is a having the edges of the sketch extruded individually (to faces). But in the context of the usual work flows, this result is mostly useless.

[r-frank]

Hello.

Since I am german and eager to learn something I first wanted to know what a non-manifold is.

So I found this document.

Looking at the Pictures "Non-Manifold Vertex in a Face" and "Non-Manifold Edge in a Solid" I would say:

> Circles or cylinders touching each other are mathematically spoken extra cases
> if the CAD-Core (in our case OCC) supports it you probably won't be able to do this Operation
in one single step
> but this is an interesting Point. ATM I don't have Access to FreeCAD but if time permits, i will do some
tests and report back

Roland

[bkane10]

Anyone have any advice on a good open source CAD package for non manifold modelling?

All the best

[NormandC]

Hello,

I'm sorry but CAD and non-manifold are totally, completely and absolutely antagonistic.

In CAD you try to avoid non-manifold like the plague. In fact all the CAD programs I know of will flat out refuse an operation that would generate a non-manifold object. That's because CAD is almost solely focused on real world design, and to my knowledge there is no case where a non-manifold object is desirable.