Re: Labels in MetaPost

> (but without font stuff) are accepted. So I conjecture that
> "3DLFmp.1" is NOT output by MP itself. Right?

Wrong.  (Sorry to be so blunt).  It is output by MP itself.  The 3DLDF code is
in the file `sample0.ldf': 
http://savannah.gnu.org/cgi-bin/viewcvs/3dldf/3dldf/Group/CWEB/sample0.ldf
It's figure 1 (what I was working on most recently).   I can't generate the MP
output on this machine, but I'll send it to you tomorrow, if you want it.

Incidentally, it demonstrates that occlusion works for the vertical rectangle
and the bottom horizontal one, but not for the top one.  As long as I've got
you "on", I hope you don't mind if I take the liberty of asking you whether
there's an algebraic formula for the curve on a plane of projection
representing the perspective projection of a circle.
(I may take to button-holing mathematicians on the street.)

> Comments anyone?

I haven't had any problems with labels using MP the way I do.  As far as MP is
concerned, that's up to John Hobby, Taco, Hans, Karl, Jacko, and the other
developers, if  I've forgotten any .  If anyone using GNU 3DLDF feels it's a
problem, than I suppose I shall have to implement support for overlays using
TeX.  It seems like a reasonable alternative to labels and I might be able to
implement it in such a way that users don't notice any difference.   Perhaps I
could add an option to determine which style to use.  I admit that I _hate_ it
when MP fails because of an error in a label string.

Laurence