With Blender, you can model using a preset basic mesh object–cone, cube, cylinder, sphere, torus, etc.–that you can extrude and reshape.

Sebastian Kurtek, Anuj Srivastava, Eric Klassen, Zhaohua Ding, Statistical Modeling of Curves Using Shapes and Related Features, Journal of the American Statistical Association, Vol. 107, No. 499 ...

3D modeling software has a notoriously steep learning curve, so Sixense and Vive Studios put their heads together and launched a ridiculously simple CAD program anyone can use.