[help-3dldf] Re: button-hole problem

[Laurence Finston]

On Tue, 26 Apr 2005, Peter Vanroose wrote:

> No.  By "projection" I mean "projection of planar objects onto a
> plane".

Oh, well.

> Certainly. But projections are the most general transformations that
> are guaranteed to transform straight lines into straight lines.

Thanks again.  This looks like a very promising avenue.  I'll see if I can
find an elementary text on projective geometry.

Laurence