[Algorithms] Re: Portal VS BSP

[Alen L. <ale...@cr...>]

>> If you are talking about building the PVS/portals directly from the 
>> tree's
>> topology, then yes. The question was about what current games were doing 
>> and
>> I only know of games using a sampling method to calculate the PVS or 
>> using
>> hand-built portals. There may be games which use the BSP's topology, but 
>> I
>> don't know of any. Perhaps someone else can think of some?
> 
> Hm... I don't have the source code of "vis" tool for Quake1 to check it 
> out, but IIRC from some texts I read a long time ago, it is just what it 
> does. It makes a BSP, then portals and then uses those portals to make the 
> PVS. Maybe I confused that with the old Seth Teller's PVS paper. Feel free 
> to correct me if I'm wrong. 

On a second read, I believe I might have misunderstood you. If you ment 
games that use BSP to build portals and then use those portals for dynamic 
visibility, yes, I don't know any either. But it certainly feasible as well. 
I used that in a renderer I implemented a few years ago for some testing, 
and it worked well. :) 

Alen