From: Brian Osman 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 Lines: 13 Message-ID: <3421D1B1.A8EF332C@rpi.edu> Reply-To: osmanb AT acm DOT org NNTP-Posting-Host: darkwing.stu.rpi.edu Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk 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