1. What's the difference between nodraw and caulk, both performance and visuals wise?
Caulk blocks in-game visibility (not te be confused with the vis compile phase), nodraw does not.
Try making an empty box room and place two blocks in it: one caulked and the other
with nodraw. The caulk brush will create the Hall-Of-Mirrors effect, the nodraw brush will be invisible.
2. What is and how do i use a func_train?
A func_train is used to let a group of brushes move around along a predifined path. Think of it as, brush drives to station 1,
brush drives to station 2, brush drives to station 3, brush drives back to station 1. Tchootchoo
You can probably find a tutorial
here.
3. Can you give me some ideas on detailing my rooms, and tips on how to do so?
The best hint I can give is: do not treat your details as details. Treat them as important parts of your map.
For example, you can build a room and put a generator and some machines inside to dress it up.
I would build a generator, some machines and build my room around it.
Off course you still need walls ta have an idea about the size and to compile the thing, but do not think of
them as fixed obstacles.
When someone builds a room he usually starts by creating the walls, the floor and the ceiling.
Next he will fill the room with details. Try something different: start with a detailed door,
a window or some other impressive construction (pilars, arches etc....)
The next piece of advise is a variant on an old saying:
compile early, compile often. Compiling your map has many advantages: first of all,
you'll spot leaks fairly early saving yourself a lot of trouble. You can also spot other problems:
if all of a sudden your compile lasts forever you can be quite sure something is seriously broken.
If you do manage to get it compiled, take your time to run around in your own map. Look at the details,
try to "feel" what is missing. Most if the time, I get spontanious an natural ideas. A door here, a pilar there...
sometimes small detail can have a huge inpact.
Show it to your friends, they might have some ideas too.