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Mail Archives: djgpp/1997/09/19/01:16:25

From: Brian Osman <osmanb AT rpi DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Allegro 3D Transformation Question
Date: Thu, 18 Sep 1997 21:13:21 -0400
Organization: Rensselaer Polytechnic Institute, Troy NY, USA
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Message-ID: <3421D1B1.A8EF332C@rpi.edu>
Reply-To: osmanb AT acm DOT org
NNTP-Posting-Host: darkwing.stu.rpi.edu
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To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

Hello,
I realize I probably should be asking this elsewhere, but it's somewhat
related. Given an object in 3D space, with an (x, y, z) center and
rotated about it's own axes by (rx, ry, rz), I'm trying to rotate yet
another point around the first point, in its frame of reference. I'm
using allegro, for all the matrix/vector manipulations, but I'm not sure
of what sequence of matrix operations is required to do this. (Actually,
the part I can't seem to remember is converting some (x, y, z) into the
correct coordinates in an arbitrarily positioned/rotated basis. Any
help? (Or is there something in allegro that will make this much easier
and I'm just not seeing?)

Brian

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