From: elf AT netcom DOT com (Marc Singer)
Message-Id: <199703211735.JAA29516@netcom9.netcom.com>
Subject: Re: John Carmack <johnc AT idnewt DOT idsoftware DOT com>: Re: Question about Doom.
To: fwec AT juno DOT com (Mark T Logan)
Date: Fri, 21 Mar 1997 09:34:57 -0800 (PST)
In-Reply-To: <19970319.192716.7391.1.fwec@juno.com> from "Mark T Logan" at Mar 19, 97 07:29:10 pm
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Sender: elf AT netcom DOT com

> Wolfenstein 3D used ray casting.
> Doom used BSP trees and a one dimensional completion mask.
> Duke3D used sector flowing.
> Quake used BSP trees, a PVS, and an edge list.

I know that PVS stands for Partial Visibility Set.  It is used to keep
track of what *might* be visible from each node in the BSP tree.  It
allowed them to make rendering of the true 3d BSP feasible on PCs.

-- Marc Singer