NewsUnrealEdFilesModsFragBULiandri Archives
BeyondUnreal Forums

Go Back   BeyondUnreal Forums > Unreal Development > Mapping

Reply
 
Thread Tools Display Modes
Old 10th May 2001, 12:52 AM   #1
Mind Maze
Registered User
 
Join Date: May. 6th, 2001
Posts: 76
Question

No, the question wasn´t what is BSP was:

What are BSP holes many people talk around?
What to do with rebuild BSP (Optimal, lame, good and minimize cuts or optimal)

I made a room with slime and a bridge there but there´s a "crack" which I don´t know what is it. In some angles viewing the slime at one side I see the HOM effect in a small part there.
Mind Maze is offline   Reply With Quote
Old 10th May 2001, 05:18 AM   #2
ZodiaK
irresponsible walrus
 
ZodiaK's Avatar
 
Join Date: Feb. 14th, 2000
Location: onboard The Mothership
Posts: 910
A BSP hole is just the thing you see as a hall of mirrors- effect, usually either a badly-designed portion of a level, a too complex brush to be fully understood by the editor or just a plain mystery...
__________________
ZodiaK is offline   Reply With Quote
Old 10th May 2001, 02:20 PM   #3
NutWrench
Registered User
 
Join Date: Nov. 27th, 1999
Posts: 212
Quote:
Originally posted by Mind Maze
No, the question wasn´t what is BSP was:

What are BSP holes many people talk around?
What to do with rebuild BSP (Optimal, lame, good and minimize cuts or optimal)

I made a room with slime and a bridge there but there´s a "crack" which I don´t know what is it. In some angles viewing the slime at one side I see the HOM effect in a small part there.
Hi Mind Maze,

BSP stands for Binary Space Partitioning. When you compile your map, the computer takes the geometry you've supplied (Add and Subtract brushes) and creates a 'BSP Map.'

During compilation, the valid player space is recursively subdivided and the results are stored in a binary tree which tells the Unreal Engine where the player can and can't go (collision map) and what he can or can't see depending on his location in the map. Because of the need to keep map file sizes managable, you can only recursively subdivide the player space a certain number of times, since the BSP map grows exponentially with each iteration. So sometimes it's possible to make NO mistakes while building a map and to still get BSP holes. Like Zodiak mentioned, this often happens in the vicinity of very complex brushes. The brushes complexity exceeds the number of BSP iterations, and so the engine can't tell if the area is actually inside or outside the map. Because of the way decorative brushes interact, sometimes moving the brush slightly can help.

Try moving the detail brush slightly and rebuilding. This can change the way the engine partitions up the space around the brush and get rid of those BSP holes. The BSP view in the 3D window can help find these holes for you. (You'll need to re-build to update the BSP.)

You can also position the brush so it doesn't actually come into contact with the wall or floor (make it "float" 1 or 2 units above the floor or away from the wall). If the Add brush doesn't actually touch the floor/wall then it won't cut up the floor/walls BSP. This is a good trick to use with decorations like boxes, light fixtures, etc)

You can make the brush a semi-solid. Only Add brushes can be made semi-solid. Switch to the wire-frame view and left click on your brush to highlight it. Then right click on it and select "Make semi-solid" from the Solidity sub-menu. The brush will turn pink if you did it correctly. Now switch to the BSP view. Remember that this BSP view was generated the last time you re-built the map so, it won't show the changes you just made(this is why it's so important to re-build after changing your map geometry). Re-Build. You should see a BIG reduction in the number of BSP cuts. Fewer cuts means the map will run faster, so this is a great way to optimize your map for speed.

The only downside to semi-solid brushes is that they don't have proper collision maps, so it's possible under certain circumstances to fall through or walk through a semi-solid brush (usually if you're touching different parts of the same brush at once, like a single brush that serves as a ledge AND a wall). You can always change a semi-solid brush back to solid if any weirdness happens.

Last of all, you can always cover up a BSP hole by covering it up with an Add brush (add a thin rectangular Add brush over the hole). It's not an elegant solution, but it works.

--Nut
When life gives you a lemon, say 'Lemons? I like lemons. What else have you got?'
NutWrench is offline   Reply With Quote
Old 10th May 2001, 08:18 PM   #4
Mind Maze
Registered User
 
Join Date: May. 6th, 2001
Posts: 76
Angry

Polygons just make me upside down. Even with grid 1 many times brushes needs to be positioned without grid accuracy and I see many brushes with 1 or 2 pixels away some other one, so when you play you see floors/walls with 1 or 2 pixels away from the correct alignment.

I´m trying to optmize the map making some complex brushes to save polygons.

I thinking in how creators takes the BSP thing to optmize games...
Mind Maze is offline   Reply With Quote
Old 10th May 2001, 10:31 PM   #5
NutWrench
Registered User
 
Join Date: Nov. 27th, 1999
Posts: 212
Smile

Try left-clicking on one of the vertexes on the brush that's closest to the brush you want to join to (so that the red pivot point appears), then immediately right-click. Sometimes this can snap the brush into place.
NutWrench is offline   Reply With Quote
Old 11th May 2001, 02:31 AM   #6
ZodiaK
irresponsible walrus
 
ZodiaK's Avatar
 
Join Date: Feb. 14th, 2000
Location: onboard The Mothership
Posts: 910
learn to use the grid. as a general rule of thumb, design your levels so that everything stays on the grid, if possible --- at least the basic level geometry. decorative brushes like "floating" boxes/stuff (that nutwrench mentioned) can be off the grid as they won't cut up your BSP. you should hardly ever have to use grid settings smaller than 4.
__________________
ZodiaK is offline   Reply With Quote
Old 11th May 2001, 04:42 AM   #7
BitBasher
Quantum Singularity
 
BitBasher's Avatar
 
Join Date: Mar. 24th, 2001
Location: The Void
Posts: 171
Quote:
Originally posted by ZodiaK
you should hardly ever have to use grid settings smaller than 4.
Agreed! I tend to work with 16 and 8 mostly. But I do find myself going down to 1 to place decorative sheets, masked textures, and pretties like light boxes. Since all these things are sheets (added typically as non-solids) I betcha that staying on the grid for these things isn't really a big deal.

BB.
__________________
BitBasher's Temporary UED Page - Lots of OUTDATED UED tutorial links, and simple beginner demo maps.
BitBasher is offline   Reply With Quote
Old 11th May 2001, 11:52 AM   #8
Mind Maze
Registered User
 
Join Date: May. 6th, 2001
Posts: 76
Arrow

Yep, I´m trying to stay in grid size of 4-16 because rooms with brush size of +4 or -8 in play it´s too small to notice.

Everytime I forget to make brushes that have size multiplier of grid size.
Mind Maze is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:13 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.

Copyright ©1998 - 2012, BeyondUnreal, Inc.
Privacy Policy | Terms of Use
Bandwidth provided by AtomicGamer