What is the best way for cutting hole in walls, like doorways or firing slots?
Also, what are the typical dimensions of a firing slot and how far off the floor should it sit and, if I’m making tunnels is there another way to pass a hollow brush thru terrain other than using CSG Subtract?
Sorry for all the noob questions. I just haven’t found too many of these answers in the tutorials.
For my personal preference, I use CSG subtract. But I make sure I inspect the resulting brushes after doing so. Most the time, it warrants no changes. However, if you already have textures on the brush, you might want to inspect all sides of the resulting brushes as well…you may need to recaulk, retext them.
By doing that, it should result to your option #2 there, most the time. If not, Ctrl+Z 
CSG_subtract is evil… Use option #2.
A good rail hieght is approx 40 units tall.
Can you explain why you think it’s evil?
If you have a simple square rectangular brush, and you substract a smaller rectangular brush out of it (in the middle), leaving you with four brushes…that’s the same thing as making four brushes yourself, isn’t it?
I don’t see why it’s so evil.
Thats just the general impression that I have gotten from the community… and I personally havent even tried csg_subtract just cause I heard so many bad things about it.
In your example though, perhaps it would work fine. But based on what I’ve heard, if you csg_subtract angled brushes (or any non-rectangluar brush for that matter) you may end up with some nasty results. Again, I havent tried it myself (and I never intend to either) becuase I can simply piece together the same thing in a relatively short amount of time and never have to worry about it being “correct” or not.
I gotcha. I would definitely shy away from subtracting odd shaped brushes, as well, but I tend to do it anyways just to see what brushes it produces, and if I don’t like it, I undo it and do it myself. :drink:
Its more of a function rather than a tool.
It’s found in Radiant. If you mouse over all the toolbar buttons up to, look for a button called “CSG Subtract” (should be close to where the “Hollow” button is). Basically what you do, is you select a brush. And when you hit the button, the selected brush will be “carved out” of any brush that it is touching.
[quote=“redfella”]CSG_subtract is evil…[quote]
looks like you got that from a tutorial for mapping in jk2
anyway… csg subtract is good in some ways… for example: you have your ground for your map… you want a square hole in this one spot that you most desired to be on the ground… create a brush that sticks out both ends of the ground… select that brush that sticks out both ends of the ground and click csg subtract… let the magic work and now you have a square hole in your ground :rocker2: … this could be different when u have terrain with hills and such or a wierd structured ground, i wouldn’t suggest using csg subtract then
Contrary to what many ppl say, csg subtract is very useful for many things. Cutting a square hole in a square brush is one of them 
Remember that you can always undo what you did, so if you manage to screw something up with subtract, you can very easilly undo it with ctrl-z.
It is NOT good for making square holes. It is NOT good for cutting polygons out of brushes. It DOES create shitty brushwork in almost every concievable situation. You CAN use it correctly, but no one here has posted an example of it.
We have also discussed it a few times here:
http://www.splashdamage.com/forums/viewtopic.php?t=3098&highlight=csg+subtract+evil
no, its FINE for making square holes in square brushes - the only problem might be if you want to mitre your brushes after the subtract - which can be easilly accomplished with the edge manipulator tool. That link shows someone subtracting with wierd shaped brushes.
csg subtract is not evil… some ppl are just too stupid to use it properly
csg subtract IS evil.
Not only can you not mitre the inner edges of your square hole after using csg subtract, but it also creates an unoptimized mess for the compiler.
Proof:
csg subtract is for the lazy.
How many people actually make their holes like that? Few, if any. Even splash damage doesn’t do that. They would make a hole like in the second picture.
Look at chavos top right image. That is the classic ‘use csg subtract to cut a square’. It also shows the classic z-fighting and overdraw you get from using it. Not to mention the higher r_speeds he already pointed out.
You should really read the link I posted.
CSG Subtraction is the favourite of lazy intro tutorials or people that have not discovered 2/3 point clipping. But in its defence I have used it on several occasions when I wanted to create strange brush shapes. Typically its the first thing that all new mappers find and lets face it everyone wants to do things the easy way. But as Chavo_one has nicely demostrated its often more trouble than its worth because of the optimization issues which will come back to bite you later on.
I suppose in the end its like all advice given, you either listen to it or not.
Sock
:moo:
Hi chavo_one! Excellent images! Thanks!
I never (seldom) use csg substract. I always (often) make holes “by hand”.
But your images make me pussled!
Look at the top right picture. This is the way I make a building wall, and the hole in that wall. Are you telling me that this is not optimal? Should I make the wall as in the top left picture?
Well, I will try it (the top left design), and have a look (using r_showtris 1 or 2). You’re probably right.
Thanks again for the idea!
// Loffy
Not only can you not mitre the inner edges of your square hole after using csg subtract
sure you can.
In many cases its technically more efficient to use the clipper, but for many things the csg subtract tool can be a valuable time saver. Just because its quicker and (potentially) sloppier doesnt mean thats its just for lazy people 