Hi David,

> For example I had an hard time to cut a surface from a projected curve, I was not able to
> do it so I had to make a shape from the original curve and use it for a boolean diff.

If the curve became non-planar after it was projected, that would cause that type of effect - boolean difference can only directly use 2D planar curves as cutting objects, they become extruded as a process inside the boolean.

If you want to only cut some limited distance into an object instead of all the way through then that is normal that you would build a shape from the original curve and use it for the boolean, that's the process for doing that...



> Many time I had to redo my shape because I made a mistake while
> constructing my shapes.

As you gain more experience these types of mistakes will become less common.



> This for example, I build the flat shape from a curve but build only one half. I then made an offset shell
> to get my thickness but the result was not correct at the middle after doing a mirror.

Yeah, that's just how offset geometry works - the offset surfaces generated from individual surfaces will only touch each other if the surfaces are smooth where they meet up.



> There is a way to fix that or do I have to rebuild my curves?

You can try to join the surfaces together before you do the offset - that will then make the offset surface get extended to fill in the missing area.



> Sometimes when I have finished my shape and I need to make a forgotten operation I'd like to
> retrieve the curves from my shape, is it possible? I'd like to have just the exterior line to be converted
> as curves, but I didn't find a way to do so.

You can extract edges by selecting them and using Copy/Paste to duplicate them, the pasted result will be separate curve objects.



> An other thing about this helmet is that I wanted to have each panel overlapping each
> others, like the real object. I suppose I have to do it with my curves or I can do it
> when my solid are built?

You can move the panels around after you have created them. But if the overlapping involves some kind of shape adjustment rather than just movement alone then you would want to have that set up with your curve structure instead.



> Here is the short lived result as I'm using the saveless version ;)

It turned out well!



> One last question, is it possible to keep the object used to create a boolean and
> edit them while still seeing the change in the resulting boolean?

No, not currently but that is something I want to add in the future with a deeper history mechanism.


- Michael