Hi PaQ,

> I remember a discussion on Modo forum, where
> someone qualify MoI mesher been "bad" because
> the topology was not sub-d friendly :)

Yes, some people seem to expect that it should magically create the same topology as a highly experienced sub-d modeler would do by hand... And no doubt, that certainly would be cool if it could optionally do that (optionally because as I mentioned previously sub-d friendly topology and sparse wireframe n-gon topology are actually different things).

Unfortunately that level of expectation is what I'd call "pretty highly unreasonable" though. It's very difficult for software to replicate things that require a kind of case-by-case human judgment to them.

There are some interesting new auto-topology tools in 3D-coat recently but that overall technique is more for a kind of all smooth blobby sculpted shape and not really for CAD solids so much, particularly with a mix of large and small features.


> Btw I dont know for C4D, by when you start messing with
> MoI topology in Modo (merging, flipping poly etc), you just
> introduce all kind of shading artefact because the vertex normal
> is not right anymore.

I'm not 100% sure but I think C4D will automatically delete the vertex normals if you do some editing operation that makes them invalid.

It would be good for Modo to do the same thing as well, just automatically delete the vertex normals if you do something that modifies the shape of the mesh like pulling some individual vertices around.

The vertex normals information is something that should be tied to the current particular shape of the mesh. If the shape changes it just does not make sense to apply the same normals from its previous shape to its shading, yet that is what happens in Modo currently I guess.

But it's also good for the vertex normals to be kept and transformed with operations where it is possible to do so, like if you transform the whole mesh (like by rotating or scaling it so the overall shape of it stays the same), or also flipping a chunk of mesh does not need to invalidate the normals it can just flip them as well. It's not really very complicated stuff, so it's kind of surprising and frustrating that this is often not handled well.

- Michael