From:	Dan <dan AT wayfarer DOT demon DOT co DOT uk>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Help! Allegro 3D maths problem
Date:	Thu, 03 Jul 1997 12:39:09 +0100
Message-ID:	<33BB8F5C.1CD3177B@wayfarer.demon.co.uk>
Reply-To:	dan AT wayfarer DOT demon DOT co DOT uk
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To:	djgpp AT delorie DOT com
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I'm using the Allegro maths functions to write a simple 3D engine. My
problem is that when I calculate rotations for the world-to-camera
transformation, I always end up with the equivalent of rotating the
camera around the *world* axes (like in Quake). That is, if you increase
pitch (look up), the camera makes a smaller turning circle when you yaw
left-right, still around the world y-axis.

What I'm trying to achieve is rotation around the *camera's* own local
axes (i.e. front, up and right vectors) no matter where the camera is,
or at what rotations, kind of like in Descent.

I have scanned Foley & Van Damme, and Abrash, but I can't seem to find
an answer.
Anyone got any ideas?

--
Dan
*******************************
===dan AT wayfarer DOT demon DOT co DOT uk====
http://www.wayfarer.demon.co.uk
*******************************

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