What's with the 32 gameunit rule?

[LinuxManMikeC]

I have played around with level design on occasion in the past, but never really got into it.  Now I finally decided to start learning how to map for the Q3 engine using Tremulous as my base game.  Too poor/cheap to buy Q3   .  So I was going through the tutorial on the wiki and found the rule that I should "always try making walls and floors at least 32 gameunits (gu) thick."  I'm not completely new to mapping, I just haven't gotten far past reading about it.  Anyway, I seem to remember reading/hearing this rule before, but I can't remember where nor the reason why.  Haven't been able to google it yet either.  Can someone please explain this rule and/or provide a link to a good reference?  Keep in mind that you don't need to worry about dumbing things down too much for me.  I have a few ideas why this is a good practice to follow.  In any case, I'm taking the tutorial author's word for it and using 32 gameunits for at least the hull of the map.

I guess as this is my first post I'll say hi now.  I've had the desire to make a complete game for  a while, but have been busy researching all the basics (gameplay, textures, modeling, mapping, programming, etc....).  Was going to use Q2 till Q3 went GPL too.  Recently I've been working on learning OpenGL and all the cool 3D math involved, but decided to take a break and work on the artistic side again.  Hopefully I can come up with something good for Tremulous in the process.  

[DASPRiD]

Thats completly bullshit. You can even make everything one gameunit thick. As you only put a texture on one part of the floor-brush (rest gets caulk), the thickness doesn't matter.

I've never heard that rule and generally use 8 units as a default kind of thickness for those sorts of things. I have not run into any problems.

True, 8 units is a good standard which most mappers keep on.

[OverFlow]

I've never heard that rule and generally use 8 units as a default kind of thickness for those sorts of things. I have not run into any problems.

[LinuxManMikeC]

Thanks for your opinions.  As I said, I could think of some possible explanations for the suggestion.  Among those were: more efficient to run calculations on certain size brushes, preventing some kind of rendering glitches, previnting leaks, etc...

The original location where I found this tutorial was in PDF format at tremulous.info.  According to that page the author of this tutorial is called "Survivor".  In the tutorial it says that the reasoning behind the 32 gu rule is "hard to explain and not at benefit to the tutorial".  I just searched the memberlist of this forum and found a Survivor listed.  Going to PM and ask directly   .  Maybe we can get an explanation.  Man, how hard would it have been to put a link in the tutorial to explain this seemingly pointless exercise?

I decompiled one of the official Tremulous maps to see how they did brushes in it.  Brushes were 8 gu thick.  The map I looked at was Nexus.  A very complex and detailed map.  I experience no lag while playing it and I don't see how following the suggestion from the tutorial would have helped this map.  And all the tutorials and maps I have seen don't follow this guideline.

Please excuse me if this got a little disorganized, its late and I'm tired.

EDIT: Removed a few stupid comments about the beveling suggestion in the tutorial.  As I stated above, I'm tired, forgot to read ahead for explanation of that guideline.  To those who may have read it, pay no attention to the foot in my mouth :-D .

[LinuxManMikeC]

OK, I was reading some more stuff trying to find the answer myself without bothering Survivor and I figured out some solid reasoning behind the 32 gu guideline.  Well the only requirement/guideline to follow is the brush should be a multiple of 2 gu.  Having a larger brush is easier to work with, but I think 32 to 64 or larger is kinda rediculous!  However, due to common texture sizes of 32, 64, 128, etc... making the brush at one of those sizes initally can be usefull, but you could then scale down the "thickness" to something more reasonable like 8 or 16 gu.  But when it comes down to how "thick" a brush is (talking hull brushes especially) it seems mostly a matter of style as the non-visible faces are usually caulked.  I do think it is easier for a noob (especially non-tech noobs) to just keep it simple and not worry about brush thickness and just use 32 or 64 gu and not think about it till they have more experience.

Anyway, a simpler way to say it is try to make all textured faces a multiple of the texture's size when possible.

Found the multiple of 2 rule/guideline at this site, as well as a bunch of other map optimization tips:
http://www.student.ru.nl/rvanhoorn/optimization.php

[Survivor]

Yes, it's a guideline. It can be as thin or thick as you like but as I mentioned try to do this.
Thin walls sometimes lead to lightbleeding problems and thick walls for floors, walls and hull make them easily selectable and they prevent parts of models sticking through the walls. This is actually meant for the main 'hull' and main walls of the map as is used in the tutorial.

Sorry for being so unclear.
I simply wanted to prevent some problems for the new mappers and telling  them that you can make them thin as you want and then explaining when to and when not to do this was far more complicated than using such a guideline for beginning mappers.

[Ingar]

I don't know about the technical issues but I use thick walls because they are easier to handle and leave you more breathing room if you need to change something later on. Connecting rooms and corridors with thick walls can also create the feeling of a heavy and sturdy construction without paying special attention to it.

[LinuxManMikeC]

Thanks for your comments Survivor.  I do agree that it is a good guideline for beginners (like giving toddlers big chunky blocks instead of legos).  I'm just not a complete noob and couldn't just take your word for it :-D .  I did try and Google the info, but it was rather elusive for me.  Luckily I was able to track you down.  Thanks for the great tutorial and for responding to this question so quickly.

[kangounator]

there's also a problem if you put a 8gu thick wall between 2 rooms (and not between a room and the void) like in DMB01 (the only map where i've seen this : ) you can see a tyrant claw "through" the wall. (the hitbox must be smaller than the model)

EDIT : sorry i had not understand it like this  :oops:

[Survivor]

...and they prevent parts of models sticking through the walls...

...