Bonjour Pierre, I do want to add some more kind of "bundled up" tools for making more operations happen directly from curves, but there are some more simple areas that will come first for that type of thing - groove cutting is rather complex, both in potentially needing a lot of parameters to control the groove shape itself and also with a fundamental difficulty of possibly generating a self-intersecting cutting shape if you have any bends in the path curve that have a bend radius that's smaller than the width of the groove.

That possibility to pretty easily have self intersecting cutting objects is a major complication for this kind of operation.

So because of that the first area of these kinds of tools will be more focused on making a direct indentation or protrusion of a shape by cutting out an entire closed outline, basically something to automate things more like the stuff shown here:

http://moi3d.com/forum/index.php?webtag=MOI&msg=3024.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=4010.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=3318.1
http://moi3d.com/forum/index.php?webtag=MOI&msg=4791.13

That's basically a higher priority to get stuff more like that working first mostly because I think that type of stuff can be done more robustly, there are a lot more potenial issues with grooves.

MoI is probably not in general the best choice for those kinds of relief/emboss type constructions like all the examples that you show - something that's polygon mesh based such as ArtCAM where they build a mesh result with elevation based off of bitmap colors or a mesh sculpting mechanism like ZBrush or 3D-Coat are just better suited for that stuff rather than NURBS modeling techniques.

NURBS modeling works well when more of the pieces involved are actually fully defined by profile curves - I know that you are also wanting to use profile curves for that style of modeling as well but it's using them in a somewhat less direct sense in that the actual geometry that you want is a kind of byproduct of the profile curve and not so much a direct interaction with the profile curve. This indirect type profile usage has the problem that it becomes poorly defined (from an exact geometric type meaning which is more how MoI is oriented on working) in certain areas of the shape, like especially something that is trying to build a sweep path will have problems in places where things go around a tight bend.

The "2.5D" type approach that ArtCAM uses is pretty well suited for those particular kinds of shapes, it's really optimized specifically for those kinds of things. So there are certainly other tools out there that could already help you to build those kinds of things much more easily than you can in MoI. But those tools are pretty specific for that type of stuff, you couldn't build a car engine for example in a 2.5D tool but you can do stuff like that in MoI.

So just in general MoI and the overall way that MoI works is not especially suited for that type of stuff you are showing, there are tools out there that are better than MoI at handling those specific kinds of jobs right now.

- Michael