Re: Visibility lists

Drizzt Do'Urden (
Mon, 22 Apr 1996 15:22:46 -0700 (PDT)

Date: Mon, 22 Apr 1996 15:22:46 -0700 (PDT)
From: "Drizzt Do'Urden" <>
Subject: Re: Visibility lists
In-Reply-To: <>

> Is this room non-convex, or is there some other reason you have two leaves
> for one room?

No, the room is convex. The reason for having two leaves for the room
is because I get the "Surface Extent > 256" error if I don't use two. I
ran into that problem before while using one leaf, even when the surfaces
were smaller than 256.

> One thing you might check tho. I had a similar problem if I used the same
> plane for more than one surface. I am not sure why. I thought any surfaces
> that were co-planar would use the same plane for caching efficiency. This
> might still be the case, but I had a lot of problems whenever I tried it.

As far as the surfaces on the planes go. My view is this: id uses
multiple surfaces on single planes, so I will too. Although currently, I
am having problems with it as you did.
Not to put down first.bsp and tworooms.bsp, but as far as following ids
format, and the rules set down in the QuakeSpecs, they are wrong. A few
things I noticed: testx.bsp maps NEVER use negative vectors for planes
unless that plane is slanted. So you will never see:
-1.000000 0.000000 0.000000 etc...
This was done in both first and tworooms. Also, tworooms defines
multiple planes for the same plane in 3D space. The quake specs say not
to do this. The visibility lists for these two levels contains one
entry...255. While the level works, this can't be right either. There's
also the fact that the surface list is basically not used. The entries
mimic the surface file. I also noticed that weapons don't stop at the
walls in tworooms. (though this could make for an interesting deathmatch)
I'm almost sure the problems with my level are related to the
visibility list, and perhaps the surface list. I have no idea how many
entries the vislist should contain. test1 contains about 494 leaves, and
has over 14,000 entries in the vislist, so it would seem the vislist
entry to leaf ratio is fairly high. I suppose there is some mathematical
formula that could be used to determine an aproximate number of entries.
I have yet to find it. Any help in this area would be greatly appreciated.