This simple tutorial is to introduce fresh mappers into understaning the universe geometry in unreal engine. Aimed at complete beginners. I'll try to keep it as simple as possible.
The Mighty Brush of endless abilities
There are two things a worker needs to do his work. The material, and the tool. Brush is the tool in here. It's the red wireframe that you see in the editor. You can change the shape of the brush in any way you desire. It can be a simple cube, it can be a whole bridge or a train. Brush is mighty. Never forget that
Add and Substract: The Ying and Yang of mapping
When you open up the UnrealEd, you see very vast black empty space. It's not empty though! Don't deceived - as you start working in the editor, the world is literally full of uber-thick matter. Instead of a builder, you must feel like a sculptor. You have a kickass huge stone to carve in, and you rub it, make holes (you can insert other stuff in those later of course) etc. etc.
The act of carving is natural, and is well based on the sequence of makers actions. Let's have an example.
1. In the editor, you substract a big cube. Then, you add a sphere inside. The effect if this action is a carved out cube with material sphere in it.
2. Let's now start with adding a sphere. Now, let's substract our cube. The effect of these actions will be merely a carved out cube.
Where did the sphere go? We carved it out along with the overlaying cube! The squence is essential.
One more thing I should mention here - adding matter to matter won't make any change in the map geometry. It won't make it double thick. The matter is matter, only one kind of it. There is matter, or there isn't. It's full or empty. Nothing inbetween. Except fluids that is, but they're a different story
Intersect and Deintersect: Add/Substract support
These two just need practice. Only then can one learn to use them properly.
Let's start with deintersect. This tool makes your brush limit to space where adding will be effective (where adding will create material).
Open up UEd and try this an example:
Select the cube brush. Substract. Move the brush a bit sideways, so that it interferes with the substracted cube, but is not covering it exactly. Now deintersect. See the result? That's what deintersection does.
Now Intersect. Always remember the first rule of Intersection! The first rule of Intersections says: Never Intersect! (unless you're really desperate) Why? Because intersection is faulty, can cause severe damage to your map, make faulty bsp cuts, etc. etc. Just don't, mmk?
Intersection does the opposite to Deintersect - reduces the current brush to the area which will be effectively substracted.
You don't have to do this, In most cases all you need to do is to prepare an accurate brush. It's better to substract too much than to intersect. Always.
I hope it will be of any help
