Hi Marco,
re:
> P.S. Michael, could you please explain more in depth what
> "CentroidTriangulation" is and how it woks ?
It comes into play when you're exporting using "Quads & Triangles" or "Triangles only" modes. The way the mesher works is it starts by making a grid of quads along the "underlying surface" of each face. Then any trim curves on the face will cut any quads they cross into ngons. If you're exporting ngons those are directly exported but if you're using "Quads & Triangles" or "Triangles only" modes, the ngons need to get converted into triangles. If "CentroidTriangulation" in moi.ini is turned on, then it will test if making a center point for the ngon and making triangles radiating out from that center point is a valid triangulation and if it is use that way. Otherwise without centroid triangulation no center point is added and triangles are formed only between the outer points of the ngon.
So for example with an ngon like this:
With centroid triangulation enabled it will add a center point and make a triangulation like this:
Without centroid triangulation, no center point will be added and only the points along the ngon boundary will get triangulated which will look like this, which has even skinnier triangles than the centroid one:
So in the above case centroid triangulation is probably better.
Where it doesn't work so well is in low poly count situations, especially where the ngon doesn't happen to have any points vertically aligned with the center like this:
Centroid style:
Non centroid style:
When there's a low poly count the center point which goes on the actual point of the original curved surface tends to be a little distance away from the other points and connecting triangles to it tends to make each ngon sort of like a little pyramid in shape, which kind of introduces a bad pattern in the poly formation. That's why it's off by default now.
If I remember right I think it was originally added specifically to make meshes that worked better with ZBrush. http://moi3d.com/forum/index.php?webtag=MOI&msg=4978.41
Also see here for a previous example:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3533.14
 Michael
