Hi Bruno,

> Do you think If I re-do those surfaces inside MOI I will be able to fillet them ?

It's possible, but it's also possible you could run into the same surface quality problem in MoI as well. If you do you might need to use something other than Sweep to construct the surface. The bad quality is probably caused by the sweep frame wobbling as it travels along those non-planar paths. I don't remember exactly how Rhino handles the rotation of the sweep frame on non-planar paths like that and I'm not certain that MoI's method would be better for your case but it might be. If Sweep doesn't work well you might need to do something like place several station curves manually and use Network instead.

- Michael