Hi Pilou,

> All was made by Moi (Symetry too)
> problem on the left
> After Symetry problem is inversed!!!

I'm not sure that I completely understand, but one thing to try is to make sure to use Edit/Join to join surfaces that are next to each other so that they become one object that has a shared edge.

MoI should create polygons with a consistent direction on them when there are shared edges.

I'm not sure from just looking the image (instead of seeing a .3dm file), but it looks like the smaller object there has different orientations along each of its 3 surfaces - this is possible if they are surfaces that are just positioned next to each other instead of joined.

If there is an object that is all joined together but is generating meshes with inconsistent normals between different pieces of the same object, then that would be a bug. If this is the problem it would help to have an example model so I could fix the bug.


> Open surfaces (transformed in poly) seems have a problem in Moi ?

Well, open surfaces should work without a problem, but there is not an automatic "outside" direction that can be calculated for an open surface, unlike a closed surface.

- Michael