Hi Pilou, this is a bug in the display. The object itself is fine (all the surfaces and trim curves, etc..), and when you reload it, the thing that triggers the bug will be gone and so it will work then. This display bug is fixed for the next beta.

> ps What is exactly history?

History is a mechanism that saves the parameters that you used to create an object. But right now the only parameters that you can change are the input objects. For instance if you do an extrude from a curve, if you change the curve the extrude will update.


> Can make this?
> Object filet, modif, modif....
> Replace at the end the first filet by a chamfer

Not yet, because of a couple of reasons. First, it is not changing an input object, it would be changing different parameters such as a radius or the type of operation. Eventually there will be some kind of UI mechanism that allows you to see and modify these types of values, but that is going to be quite complicated to finish so it won't be ready anytime soon.

The other thing is that when you do a fillet, the original object (before the fillet) is deleted. The history mechanism needs to be able to find the original object in order to apply changed parameters to it. I have some ideas on how to make this possible, but again it is fairly difficult so it will be a while.

There is a different style of CAD software called a "Feature-based parametric solid modeler" which is very much designed to operate like you're asking for. Some examples of this are SolidWorks, Alibre, Inventor, Pro/E, etc... MoI is not really set up to do exactly the same thing as these.

- Michael