Re: Standardizing coordinate systems, units of measure
Thu, 4 Aug 94 16:12:33 -0500

Eric Van Hensbergen <> writes:
> coordinate_system {
> units: 1000.0; // scale: 1 unit = 1000 meters (or a kilometer)
> horizontal: +x // x goes from left to right
> verticle: -y // y goes from bottom to top
> depth: +z // z goes from out to in monitor wise
> }

What's the difference between this "coordinate system"
(as you call it) and a rather limited brand of transform?

You are still implicitly defining a standard coordinate
system ("horizontal" relative to what?).

The notion of coordinate system becomes more meaningful
when your virtual reality is inside other manifolds, where
the choice of coordinates is more arbitrary -- to the extent
that different choices might not even be related by the
projective transforms that graphics hardware can quickly compute.

Paul Burchard <>
``I'm still learning how to count backwards from infinity...''