Perhaps the best feature in Doom Builder is the ability to fly around your map and spotting errors without having to test your map everytime. In your map, either go to mode -> visual mode, or press W on your keyboard. Depending on where you placed your map, you might see a black hole.
Use the mouse to look around, and the keys ESDF are your WASD for manuevering around your map. In this mode, your crosshair will highlight either linedefs or sectors. 3D mode is also excellent for applying textures as it allows for flood filling (mass CTRL+V at a time). To exit visual mode, press W again.
If you right click on something you're targeting, an alternate window pops up with more options. (Which will be explained later) Let's go ahead and change the floor heights. Point your crosshair at a floor and use your scroll wheel. You should notice the floor moving up/down and some red <!> appearing on the wall, which represents missing textures.
Each click of the scroll wheel is 8px in height. To put this in context:
- the Doomguy can walk steps that are at most 24px tall.
- the Doomguy needs 64px to move around
The steps pictured here are 16px tall. You can repeat this step as many times as you want to create a descending stairs effect.
Now, I messed with the other room. I made a drop 128px tall, and raised the ceiling by 128px.
Every individual sector can have its own height, and every wall linedef requires a texture. Time to texture the map! Head back over to your first room, and right click on the <!> You should get a popup window.
The properties box is for some general settings which define a line.
Impassable - Neither monsters no players can pass through, but hitscans and projectiles can. Useful for sealing off areas and making fences.
Block Monster - Blocks only monsters, but not players.
Double Sided - Indicates that the linedef has two sides. Doom Builder automatically sorts this out for you, so don't worry about it.
Upper/Lower Unpegged - "Pegs" the texture to the floor, for both ease of alignment and door tracks.
Secret - Marks walking over this line a secret.
Block Sound - The line acts as a sound insulator, and prevents sound from passing through the line. You know how when you punch and all monsters in the map can hear you? Using this option in specific areas will prevent that.
Hidden - Makes it so that these lines do not show up when hit TAB.
Shown - Makes it so that these lines are already drawn when you first start the map when you hit TAB.
PassThru - Allows the user to press a switch behind a wall. Not necessarily press two switched, but penetrate a surface.
Press the sidedefs tab. You should notice some big <!>. Click the <!> and texture manager will open up showing you textures that you can place on the wall. Doom Builder has some predefined categories, so head over to "steps," and double click "STEP5."
Press OK, and OK again. Congratulations, you've just applied your first texture!
Now go ahead and texture the floors/walls as you see fit. I want a techbase map that turns into a sewer, so I put a carpet and some slime floors. You can copy/paste textures using CTRL+C and by clicking the mouse wheel. You can floodfill all of one texture by pressing shift + mouse wheel. This is what I ended up with.
Pretty cool, eh? You can exit visual mode by pressing W again, and you'll notice that the floor textures from earlier have changed to reflect what you've just chosen.
This concludes the section! In the next lesson, I will cover thing placement.