Standardizing coordinate systems, units of measure

Randy Stiles (
Thu, 4 Aug 94 13:54:07 PDT

Date: Thu, 4 Aug 1994 14:43:26 -0500
From: (Linas Vepstas)

> I still want Y up.

Personally, I always thought GL screwed up by making z go into the
screen, and that this was an opportunity to fix it ...

Every textbook on geometry ever written has Z pointing up. But
the default GL camera has Z pointing into the screen (that's not
even a right-handed coordinate system !!!). I don't see
that we need to confuse GL's default camera orientation with a
300 year old coordinate system convention. I vote to stick to the
coordinate system every mathematician and every physicist in the
world uses, instead of doing something non-standard (again) in graphics.
I still want Z up.

Ah heck. I hate arguing about stuff like this ...

So do I, and deep down we all know we can put in
some extra transformation to get it our own way,
but I hate living with it for years on end, so
I'll add my $0.02.

Z is up, X and Y are on the plane. For the screen
this means Y is into the screen, and X is horizontal.
SGI Performer works this way, and I for one am
EXTREMELY glad they broke from the GL convention
that their own company established.


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