"dynamic extrude"

 From:  Michael Gibson
3966.15 In reply to 3966.14 
Hi Burr,

> It just seemed how all the box modelers are working...

Not quite though - box modeling tends to work by extruding polygon faces, kind of punching an existing face outwards into a protrusion and optionally shrinking or expanding the end of it.

That's a pretty different thing than a "draw curve" / revolve type method like you've been describing.

- Michael