Hi Rogurt, thanks for posting the file.

> A projection of a spline drawn in sideview (cyan) will not
> give good results neither on the forefoot nor on the
> other side.

I get a result that looks like this:



Can you maybe describe what is not good about those results, nothing appears bad there to me with just an initial look over it.

Note that in the project command since the curve you are projecting is not planar, you will need to place 2 points inside the command to define the projection direction. Usually it is easier to project planar curves, but your curve kind of bends and is kind of warped in 3D instead of being a planar curve.

You can make it planar by selecting it and squishing it flat using one of the corner edit frame grips until you get "flat snap", see an example here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3378.4

- Michael