Problem #2 - ReadClipHull: MAX_MAP_CLIPNODES
Solution -
I encountered this problem after I had completed my first version
of the .MAP. The first version had about 2000 brushes. However, I wasn't
completely satisfied with its appearence. The walls were all very flat --
a little too Wolfensteinish. The textures I used for each of the seven floors
were "horizontal" -- that is, their lines ran from side to side. So, I thought
of a neat trick using BMP2MAP to help fill out the walls. I outlined each wall
with a window color. I then adjusted the window tops and bottoms to be
properly aligned with the horizontal lines in the textures. The end result
was walls that that had a nice 3D effect. However, it created this MAX_MAP_CLIPNODES
problem.
The limiting number was 32767, since clip nodes each have an ID represented
by a short int. At first, I thought this might just be a limitation of the
version of QBSP that was used. However, further investigation revealed that
this was actually a limitation of the .BSP file format -- so upping the level
in the QBSP compiler would not have helped.
I thought I had found a neat solution at one point by eliminating the clip
nodes in what reported as being an empty hull. However, John Carmack at id Software
indicated that this wasn't an acceptable solution, so I had to figure something
else out.
In the end, I ended up using the "skyed window" option of BMP2MAP
using the special "CLIP" texture for the sky for the small lips on the walls.
I left the larger lips empty, so players could actually hop up onto the lip.
Below are my postings to r.c.g.q.e on the subject.
jkp2866@unix.NOSPAM.tamu edu (Jack Perdue) wrote:
>Howdy all,
>I posed this question to the gods, but I know they're busy,
>so I thought maybe one of my fellow mortals might be able to help.
>If QBSP indicates:
>Hullnum 2: No entities in empty space - no filling performed
>is it safe to toss the clip nodes in the .H2 file?
>At present, the .MAP I'm working out has about 38K clip nodes
>between .H1/.H2 (26K/12K) when QBSPed. Thus, I receive a
>MAX_MAP_CLIPNODES error at the end. From what I can glean
>from the Unofficial Quake Specs, there is no way to overcome
>the limit of 32767 in the .BSP file because the child node
>id's are short ints. Is this correct?
>Some quick testing has revealed that if I edit the .H2 file
>to have 0 clip nodes after receiving the above message, and then
>run QBSP with the -usehulls option, everything _seems_ to be okay
>(i.e., I don't fall through the floor, I don't walk through walls).
>It _seems_ the .H2 file only contains the clip nodes
>from the outside, and since nothing can get outside, they are
>not needed. Is this true?
>Any answers y'all can provide are greatly appreciated.
>Gib'em,
>jack (aka Silicon Slick - 300 miles and 5000 clip nodes too far from Quakecon)
>si_slick@cy-net.net
>Clan 13th Man - ../../fromhttp/Clan13thMan/
>ps. FYI, the level I'm working on is currently documented at:
> http://parasol.cs.tamu.edu/people/jack/fromCS/BrightCTF/
> My last successful build had about 2000 brushes. The version
> I would like to do has about 6000.
Howdy all,
Well, one of the gods spoke to me (actually it was e-mail... and he's
not quite immortal yet... but his initials _are_ JC) and here's what
I've learned.
1) The empty Hull 2 problem (I didn't think it was a problem) is caused by:
"That usually means that you don't have any entities more than
32 units away from a wall. Drop a light in the middle of a room
and it should go away."
Well, I'm sure that I had such a creature (indeed I do), and
replied thusly.
2) In addition, I asked of the significance of Hull 2/the .H2 file (since
I was pondering the effects of my statements above). The short and
sweet response was:
"No, every map needs a hull 2."
So... I'm screwed... too many freaking clip nodes, whatever the heck they
are, so I can't do what I set out to do...
Bull[snip], I'm not buying it... (my defeat that is)
So, create a cube. QBSP it. Analyse the clip nodes. Okay. Create
a hollow cube. QBSP it. Analyse the clip nodes. Okay. Read the source
to QBSP. Read it again. Keep reading it even though I don't have a clue
what a surface and an edge and a node are. Okay. How about...
A SOLUTION!!!
Part I: Eliminating the empty hull error -- 32 units may be right for the
horizontal, but looking at the .H? files, I'm not sure that's
sufficient on the vertical. For example, I have a light in the
middle of a room, but the ceiling is at +60 to it's center and
the floor is at -60 to it's center. That should be at least 32
on each side. So, I'm thinking the clip nodes on the floor
are much higher at this point.
Anyway, suspending an info_intermission in the middle of a cavern
has seemed to do the trick. I didn't think it was a problem,
but I'm only knowledgeable enough to be dangerous. ;)
The fact I didn't get the empty hull 2 message signficantly
decreased the number of clip nodes. However, it wasn't enough...
until...
Part II: I figured out a way to reduce the number of clip nodes from
39K to 25K (the .MAP is still ~6000 brushes) by thinking a little
about what they were used for.
Basically, I've filled in the gaps using the CLIP texture (whose
very existence is to define clip nodes). Here's an example in
ASCII (W=wall, C=CLIP texture):
WWWW WWWW
WWWW WWWW
WW WWCC
WW WWCC
WW WWCC
WW o WWCC o
WW /|\ WWCC /|\
WWWW | WWWW |
WWWW / \ WWWW / \
old new
wall wall
So, instead of three clipping surfaces facing the player on each
wall, now there's only one (at least that's my present theory).
Anyway, it works and I'm a happy camper.
Thought I'd pass that along. I'll go away now (you wish ;).
I'll be buried in my .MAP if anyone needs me.
jack (aka Silicon Slick)
si_slick@cy-net.net
Clan 13th Man - ../../fromhttp/Clan13thMan/
ps. using wQBSP/ARGHLITE/RVIS, a -fast (no -extra) build only took
two hours on this latest version, if anyone is really interested.
"Size isn't everything." :)
