Hi Tommy,

> no, XSI does it correctly IMO.

I thought the way it was doing it was causing a problem for you?

It is understandable that under a general edit operation such as moving a single point of the mesh around, that they would throw out the pre-calculated vertex normals for that since it is difficult to figure out how to re-orient them to adapt to the subtle change in shape.

However, for other operations that do not change the shape they should try to keep any custom vertex normals in place.

For example, moving or rotating the entire object - they should not discard precalculated normals in this case.

Flipping is the same kind of thing, flipping does not change the shape so it is easy to keep the precalculated normals in this case, just multiply them by -1 to flip their direction as well.

The problem is that XSI is treating flipping as a kind of "custom edit operation" when it is actually a "vertex normal preserving edit operation".

It would be great if they would fix this up in XSI - if they did you would not have run across a problem in this case.

I didn't really worry about flipping initially since I thought any advanced polygon modeler would be able to handle flipping without causing any problems since it is such a basic operation, but it turns out that is not the case. Actually Cinema4D has the same problem as well.


> EDIT2: I spoke too early. It seems that of 3 bottles in the scene, 2 are correct and
> one is wrong - and which one seems to be random...

Can you please send the model files to me at moi@moi3d.com, I'll take a look and see what's wrong.

My guess would be that the bottle didn't get quite fully sealed into a solid?

- Michael