Re: PVS generation

Uffe Friis Lichtenberg (
Wed, 12 Jun 1996 18:01:30 +0200 (METDST)

Date: Wed, 12 Jun 1996 18:01:30 +0200 (METDST)
From: Uffe Friis Lichtenberg <>
Subject: Re: PVS generation
In-Reply-To: <>

On Wed, 12 Jun 1996, Bernd Kreimeier wrote:

> Another,
> even more important advantage lost is hierarchical
> clipping (entire subtrees) against the view frustrum,
> in object space.

But using a BSP certainly isn't the only way to subdivide space
hierarchically. I have given it a lot of thought and I can't seem to
understand why a BSP should be so much more effective than a portal-based
scheme with a graph connecting the convex hulls.

(Like Descent and probably Duke Nukem too.)

> The world has to be static if a PVS is used.

Exactly! A much too big disadvantage IMO!

> There is no way around hierarchical spatial subdivision.
> Whether you use BSP, Octree, or something else is up to
> you...

Of course. Unless you restrict yourself to ridiculously (sp?) simple
geometry. Anyway, I'm drifting off-topic now I guess. I think I will give a
graph-based approach a shot sometime. Just to see the difference.

> > Calculate PVS on the fly, like every serious game does ;-)

Agreed! (:

Uffe. [uphfe]

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