Hi Alcides,

> So, the solution is to design the model with developable surfaces.

This is pretty huge constraint, any general surface that is created by lofting, sweeping, revolving, etc... will not be developable - to only design with developable surfaces means applying various specific constraints to the way you go about designing your model.

MoI was not created with these particular specialized constraints in mind, so it would be a somewhat difficult task to achieve this result of only using developable surfaces with NURBS surfaces, using MoI anyway.

But if you do a conversion to polygons it basically removes the need to do this kind of specialized constraints in the construction of your NURBS models, so that is likely to be a much easier route for someone who is not going to be focused on spending a lot of time manufacturing their NURBS models.

If you are manufacturing things made out of cut steel, etc... then certainly that is another case and investing the considerable time that will be required to learn and train yourself to only model with developable surfaces would make more sense in that case.

- Michael