Hi Pilou,

> There is a Joint Push Pull inside SketchUp who Extrude the curvated ribbon face above ;) <...>

SketchUp doesn't have actual curved surfaces, only flat polygons.


> As we can extrude these flat vertical faces ribbon (even they auto intersect during the extrusion)
> it's tempting to make the same with the curvating above! :)

If you divide the curved surface into flat pieces then an extrusion for each flat piece will be better defined.

Since MoI works on true curved spline surfaces there are different kinds of issues with possible self intersections.

- Michael