Hi Pilou, yeah a deformation of a solid can be a somewhat different thing.

But David mentioned 2D AutoCAD - AutoCAD has what is called a "Stretch" command that is meant to alter a 2D line drawing by moving only a portion of the vertices instead of all of them (as shown in the video). When in the AutoCAD Stretch command you make a window selection and only the endpoints within that window are moved around, with the other ones remaining in place.

In MoI if you want to do the same thing to a 2D line drawing, you just turn on control points and select the ones that you want to move and don't select the ones you want to remain in place. Then you can use any of the transform commands or dragging to make the alteration. That then ends up with the same result as "AutoCAD Stretch".

In MoI turning on control points allows you to select only some vertices so that transforms only alter just those points and not all points in the object.

- Michael