View Full Version : HOW do I fix BSP holes?

17th Mar 2001, 01:15 PM
/me asks how to fix bsp holes?
I have some in my map. I want to get rid of them. what do i do?
I know ive de-intersected and all that. I dunno why they are there. I noticed they are always in the same spot? AND I CANT GET RID OF THEM!

17th Mar 2001, 01:37 PM
Well, if you've also used semi-solids for as many of the additives as possibly possible, then you're having problems because of coplanar surfaces. These can cause problems.
There sadly is no general recipe to get rid of BSP holes; you'll just have to try working around them.

17th Mar 2001, 02:06 PM
If you didn't use semisols at all then try to convert some of the solid brushes...

Also try setting the evil brushes to last in the BSP order.

17th Mar 2001, 03:17 PM
Make sure you don't have too many overlapping solid brushes.

Make sure you havn't subtracted from a semisolid.

Make sure you haven't (de)intersected a sheet brush.

Check your 2D ed brushes as these are sometimes bad.

Check your collision hulls don't intersect the walls.

Fiddle with the slider under BSP in the rebuild settings dialog.

After vertex editing, check that all the surfaces have corners which are coplanar.

The list goes on..........

17th Mar 2001, 05:31 PM
Welcome to the world of unreal editing

17th Mar 2001, 10:12 PM
NEVER use semi or non solid brushes. They can really kill your map unless you REALLY have to use them. (like for zone use).

18th Mar 2001, 01:30 AM
Deathman are you kidding? i use semi solids and non solids like mad, it's the only to make over laping textures and since they don't split the bsp they lower node count(in most way, there are exceptions) and i still havent had a bsp hole

18th Mar 2001, 06:34 AM
I personnally never use SOLIDS in my maps.Always semi-solids.
(but I agree this is not a good habit)

18th Mar 2001, 08:27 AM
Only semi-solids???

That's dangerous....D

18th Mar 2001, 06:26 PM
yeah everything might collapse one day...

19th Mar 2001, 11:49 AM
Even the good old MIR...BTW did you bring the parachutes for the landing? :D

19th Mar 2001, 02:13 PM
Man and I just GOT here, geeze, well, when are we moving to ISS?

I use a good healthy mix of everything and I rarely have a BSP hole, except for coplanar bipolar textures on the z scaled plane! (matching coplanar walls)

Ren Höek
19th Mar 2001, 05:43 PM
clipped brushes are also easily to be the couse for bsp holes, especially after scaling and rotating them


The ultimate novice
19th Mar 2001, 09:19 PM
I like the way you think, NP! Methinks conversation with you could provide endless hours of entertainment.
Oops, the subject. Um . . . Uhh . . . BSP! :D

Ren Höek
20th Mar 2001, 05:16 PM
AAAAAAAAAAAAAAAAAAAAAAAAAARRRRRRRRRGGGGGHHH, they are everywhere!!!!!!!!!!!!!!!!!!!!!!!!!!!!

20th Mar 2001, 06:22 PM
Uhhh... what are BSP holes???

20th Mar 2001, 07:01 PM
God Ren,
Every time I see an attached image of the editor by you, I'm itching to see what it is your making. Intricate looking ****. Can we expect something soon ?

20th Mar 2001, 09:15 PM
yea, umm ren, those are pretty serious....
you need to fizx those :D

Heres a pic of the map im working on right now:

20th Mar 2001, 09:21 PM
Ack it didnt attch my pic

20th Mar 2001, 09:24 PM
Oh i see it was to big....
One more time then time for bed:

20th Mar 2001, 09:43 PM
I decided to correct the gama on these pics of Doc's. They were too dark for me to see. Now that I CAN see them...Looks like it's gonna be a good map Doc. Good luck.

The ultimate novice
20th Mar 2001, 11:10 PM
Originally posted by Mclarenlover
Uhhh... what are BSP holes???

BSP holes are the nastiest things in the universe. When veiwing a map, they can either look like quasispacial tears in basic matter through which an endless void is seen, or a framerate devouring Hall of Mirrors effect that captures what you see, and duplicates it over itself until you look away. There is no simple way to cure, or even prevent these beasts; one must learn to cope with their presence. To answer your question, no one knows what BSP holes realy are, and we're all searching for the truth.

21st Mar 2001, 05:55 AM
Originally posted by The ultimate novice

BSP holes are the nastiest things in the universe. When veiwing a map, they can either look like quasispacial tears in basic matter through which an endless void is seen, or a framerate devouring Hall of Mirrors effect that captures what you see, and duplicates it over itself until you look away. There is no simple way to cure, or even prevent these beasts; one must learn to cope with their presence. To answer your question, no one knows what BSP holes realy are, and we're all searching for the truth.
mmhhh ....this is totally illogical captain.

21st Mar 2001, 11:58 AM
We DO know what BSP holes are. There is no way to correct them but you CAN avoid them. Or with some minor changes (hopefully) you can kill them.

21st Mar 2001, 12:02 PM
The Unreal Engine uses Binary Space partition trees to store 3d data. (This could have been done by several other ways like octal trees...etc. I don't want to make a lecture on data systems ) So imagine that the whole level is made out of a large sheet of metal or sth. Now you would need to fold the sheet to form rooms, walls...etc like in origami. THis is done by dividing the superspace into Sub-spaces by assigning nodes to key locations of the superspace. Then the nodes create convex parts (segments, polygons) from the superspace they can be sorted into a tree. With this method the engine can determine which areas of the map are solid geometry and have collision and which are not.

Sometimes the BSP gets messed up and certain parts will lose collision, get collision or partially lose collision. When they lose collision you'll be able to walk through walls fall through floors. If an area gets collision then you won't be able to walk into those areas and it is likely that you will see black polys around those areas, since those polys are "out of the BSP" and they don't get textured this way. If something partially loses collision that means that the borders of the collision are killed and you are able to walk into solid space. Since nothing can exist inside solid space you'll get killed.

THere are several methods for getting rid of BSP holes.

-Simplify the geometry in the area

-Use more semisolids (They don't cut up the BSP so they can't cause BSP errors in solid geometry but they can mess around with other semi-solids and non-solids)

-Try to reduce node count (semisols, build settings...)

-If additive brushes get BSP errors then it often helps if you put them to the end of the BSP rebuild sequence. (and sometimes changing them to semisol too) Note: if something is at the end of the queue then if it has subtractions inside then the subtraction will ba applied first and then the added brush will fill the space. So nothing will happen...you'll have the brush unhollowed.
You would need to intersect that brush first and add it afterwards.

-Zone off the area. THis way the geometry inside the zone won't be that complex.

I hope that it helped....
If you have any questions just ask.

21st Mar 2001, 01:28 PM
Or one way is not to have high ammounts of polys/nodes,

A BSP hole is basically a place where the walls CEASE to exist, In fact, I am working on a map that will PURPOSELY incorporate these beasts into the map,

21st Mar 2001, 01:35 PM
You can have tonloads of polys/nodes without any errors...but it will be HARD. :D

21st Mar 2001, 01:58 PM
maybe YOU could make a map with loads of poly/nodes w/ little or no errors but then again, that's you! I sure can't, I cna make a VERY low poly/nodes map and have BSP errors.

21st Mar 2001, 02:43 PM
Gosh Guys, I was just joking about the BSP hole thing, but I'm sure there are other people out there that were wondering what we were talking about... so all your time won't go totally to waste... I wasn't expecting so many responses...

21st Mar 2001, 02:57 PM
Yeah, sure...it's good for anyone who reads it.

Ren Höek
21st Mar 2001, 03:58 PM
thanx 4 the extra knowledge

Dangler: my map is not even half way done, when I get this far, I probably won't be able to edit it normally on my machine (not to mention run:( besides, I'm doing allmost all the textures myselfe and the existing textures I do use, I often have to change to fit the colour of the rest of my map. It's a CTF game, a huge spacecraft, "ohwned" by the bleu team and a little spacecraft, landed on one of the flightdecks of the large spacecraft and squat into it to take over the ship (well actually just to capture the flag, and the bleu team does the same, and.... ohw you are allready fammilliar to the ctf gaming:)

besides, I have a bsp problem with it right now, i deintersected a added brush to use it as a subtractive brush, only now I have to substract some more and it couses bsp holes, and I have allready saved over the old additives, so I probably have to build them all over again, just gonna try some brush clipping first.

Dr. Bot:
Nice truck! the invironment with the truck in it makes me think of half-life

(excuse my anglais, although I looked up one word, I probably used it wrong aswell:D)

21st Mar 2001, 04:44 PM
That sucks man I hope you get it worked out. Well I will wait as long as it takes for you to finish :) One thing I just started doing, because I did the same as you and saved over some things I wished I hadn't, I make a folder for my maps brushes and save them ALL !! 2D shapes and 3D brushes, so if I ever have to go and change say a whole section I have them safely awaiting my command :) Also, not intentionally, I find I have about 6 saves of my map, lol, and if I am not editing for a couple of days I can't remember which one is the one I wanted to continue with, LOL. Well, about the subject of this thread :), so far every BSP encounter I've had, I've been able to fix by smashing my fingers with a hammer, not really ;P I just order the brushes first or last or maybe move the brush 1 unit this way or that. Now I'm still working on my first map ever, well 2 maps, I'm making one for Rune at the same time when I get stuck or pissed at my UT map, and I wanted to do all this fancy stuff, and it's taken more time to screw with all that **** than maybe it's worth, I mean it's a labor of love for sure but I'm thinking I'm going to start excepting things more simplistic so I can move on and create more. I just hope that when I'm done I can actually get someone to play them with me. :(