k, hopefully this tutorial will give people an idea of how to progress after they've made their first map out of basic cubes and cylinders. A lot of people say "Oh you should use the 2D shape editor for most of your shapes" I disagree entirely, what can happen is this:
Needless to say, this is built entirely with the 2D shape editor. Yes ok, it is one step up from using basic cubes, but it still looks ugly (Even without the horrible textures :p). All it is, is just a bunch of random 2D shapes extruded and thrown in. The corridor is a classic. "Oh, I need a corridor, /me loads 2D shape editor and makes a complex shape, /me extrudes it by 1024 /me adds a strip light so I don't have to go adding light fixtures along the length of the corridor". The result is a basic corridor, which looks incredibly boring because it's so long, and there's nothing to break up the long surfaces of it.
The lava pit is also kinda typical, need something to fill up the floor space so I'll just subtract a random 2D shape. Sometimes people will also add a grate over the top so you can walk on it too but it's stupid, because it doesn't tie in with the geometry of the room.
This technique also leads to a lot of brush scaling too, because when you use the 2D shape editor, you can't relate the size of a shape to the rest of your map and some people are too lazy to modify the whole shape to make it smaller so they just scale the brush down. This has a lot of problems of it's own.
Of course, I'm not saying never use the 2D shape editor, it does have it's uses, but the more you get used to using alternative and quicker methods, the less and less you will have to use it.
Tutorial Starts here :)
k, now I will go over creating a basic room from start to not-so-near finish using mainly cubes and sheets. (Yes I will be using Richrig for this tut because I am too lazy to search through my texture dir. for other good 3rd party tex packs right now :p You can use any texture pack you like of course)
You will need to be able to vertex edit and brush clip. If you can't vertex edit, read this (you will want the second technique on that page for 99% of the time). If you can't brush clip, go here (We will only be clipping the red brush, though you might find a use for regular brush clipping)
Let's start by subtracting 2 cubes the same size on top of each other. Give them different wall textures so that there is a bit of variation. (I used two 256x1536x1024 cubes)
There will be some limited Z-axis fighting in this room, let's add platforms on either side by adding 2 cubes (256x1536x256):
OK, if you look at the edge of the side platform areas, you will notice that the metal beam seems to be painted on. We can trim it off by adding a 32x1536x32 cube along the length of the platform. Note there is no need to subtract the brush first, just add it:
Try not to leave any edges untrimmed in your map if you can help it and if you don't have to many polys already.
Now, this room is kinda boring, it looks too long. The surfaces are too long and plain, we need to start to break the length of the room up a bit. Let's subtract 2 256x512x1280 cubes (You could do it with 1 cube but we have to use 2 on top of each other otherwise the wall texture won't match up. (No need to intersect, that would make the brush more complex, it's fine as it is)
Now there is a huge chunk taken out of our side platforms. Let's fix that by making a sort of bridge on either side.
Using 32x512x192 cubes:
OK, this is in need of some major trim. Using the same technique as before:
Now, that bridge still looks awfully plain, lets add some bars either side of it. Make a brush 32x64x32, vertex edit one end and add it so it's like this:
Note: You can get the poly count by typing Stat fps into the command box at the bottom of the screen and pressing enter. The stats will show up when you next click on the 3D view.
To align the texture on the side btw, rotate it by 45degrees (there's button for that in the surface properties) then enter U scale of 1, and a V scale of 0.707 and press the apply button. (You can calculate that number using Pythagoras' theorem but I'm no maths teacher :p)
Alternatively you can use Tex align, easier but slower to use. If you remember 3-4 numbers for texture alignment it's 200x quicker.
Anyways, moving on. Do the same for the opposite end of the bridge and add a 32x384x32 cube in the middle to complete the bar. Select the 3 brushes and duplicate them for the other side of the bridge, then Duplicate the 6 bar brushes to the other bridge (NOT copy and paste, it's buggy and can cause horrible errors)
Now, that's the bridges finished. Obviously, if they were wooden or stone you'd need to add some supports underneath to keep them up but these are metal so you can get away with just what we've done.