Path: chuka.playstation.co.uk!scea!greg_labrec@interactive.sony.com
From: Wilf LaLonde <wilf@objectpeople.on.ca>
Newsgroups: scea.yaroze.programming.3d_graphics
Subject: Re: Wireframe stuff
Date: Wed, 03 Sep 1997 22:31:29 -0400
Organization: The Object People, Inc.
Lines: 21
Message-ID: <340E1D81.12A0@objectpeople.on.ca>
References: <33DFD095.4CA05698@ix.netcom.com> <33e022f2.49958763@205.149.189.29>
NNTP-Posting-Host: 205.189.159.246
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.01 (Win95; I)
To: Mario Perdue <mperdue@hrtc.net>

Mario Perdue wrote:
> 
> ... To do a perspective projection. You can use the
> following:
> 
> x_screen = d * x/z;
> y_screen = d * y/z;
> 
> where:
> 
> x_screen, y_screen    is the screen location
> x, y, z               is the 3D location
> d                     is the viewing distance from the screen
> 
>But this won't work if you want to draw 3D lines on top of
existing 3D objects (e.g., to SELECT it). You need the
correct camera to screen transformation that is buried
somewhere inside the renderer. Perhaps you know how
to get hold of it???

Wilf