Excerpts from ishi soichi's message of Sat Dec 29 10:00:35 +0100 2012:

> I want to draw 3D objects efficiently.

There is ctrl-shift-m which comes closest - however I guess they just
used a real 3d application. Blender sketchup (google) can be downloaded
for free. blender is open source, sketchup I don't know exactly.