Making levels for video games, or mapping for short, involves using a map editor (i.e. level editor) to design the map (level) and a compiler to convert it into a format the game can understand.
In this case we will be using GtkRadiant as the map editor, q3map2 for the compiler (included in modern versions of GtkRadiant), and Return to Castle Wolfenstein as the game to make maps for. For more advanced work an image editor also comes in handy, and other tools may be introduced in advanced tutorials.
You can install using either your CD/ISO or Steam, but if you're using a newer operation system, idtech3 games may not run correctly. You can use ioquake3 in place of the Quake3 executable, and iortcw for RTCW.
You can run the installer or extract the standalone .zip to a folder of your choice (sometimes called a "portable install"). The latest versions need separate "content packages" installed for the specific game or games you are going to be creating levels for, but the standalone version comes with all packs. During the install, depending on the version, it may ask for a Quake 3 folder. If you do not have Quake 3 installed, just click OK and when you get to the part to choose what to install, untick the Quake 3 boxes.
If you haven't installed the games to their default directories, make sure to change the directories during the install process. If your having problems with the installation, or problems during any of the tutorials, do not hesitate to search, and then ask for help on the Forum. When using the installer, files for Radiant will be placed in RTCW's main folder as well as its own folder in C:\Program Files\GTK Radiant, including the executable.
q3map / q3map2
q3map is a compile tool, converting .map files into .bsp files which are readable by the game. As its names suggests, it was made for Quake 3, but it has been updated for RTCW. q3map2 is a much improved version that adds many extra features, including compile speed enhancements and lighting improvements. Make sure you have the latest version to take advantage of these. If you use the standalone Gtk Radiant 1.6 you'll find q3map2.exe where you extracted Gtk Radiant to, but if you used an older installer you can find it in the radiant folder within your RTCW's main folder. The entire program consists of one command-line executable named q3map.exe. Any time you update it, you should back the old one up by either moving it to another directory, or renaming it to something like oldq3map.exe incase the new version does not work for any reason.
There are multiple ways to use q3map/q3map2, the easiest of which is through Gtk Radiant's built-in BSP menu. Other options include using a batch file to provide greater flexibility and reduce memory usage, or a separate front-end GUI program. Make sure that they are made to work with RTCW. Some examples are wolfcompile, q3maptoolz, and q3map2build.
This is essentially all you need for mapping. RtCW is installed with a simple layout. It installs by default to C:\Program Files\Return to Castle Wolfenstein and stores all content in the subfolder called main. Here you will find maps where you should save your maps and keep your compiled maps. Then you should have a models folder which will contain map models that come with the game, followed by scripts to keep your shaders in. For development you will want to make a textures folder for storing custom textures. Shaders are special scripts for some textures to give them different properties than the default, such as what sound is made when you walk over the texture.
Additionally, if you would like to keep your game install cleaner, you can make a separate folder in the same spot as main to store your development work. You would then need the same sub-folders as what's under main, and create a shortcut to run your game with "+set fs_homepath <devfolder>" at the end of the .exe entry. This can also be used for mod development, but it gets more complicated.
You should now have installed GTK Radiant, along with q3map if you needed to update it. Radiant nicely contains all the shader lists, map objects and the project file you need to get started. At this point you should see the screen to the right (Fig 1) once you start Radiant. Project files have all the settings that Radiant needs to know which game you are making levels for. Those settings are beyond what this tutorial covers.
The first things you should notice are the small windows, sometimes called viewports. If you have never done any 3D work before, you may be confused by them. On the other hand, if you have done 3D work in the past, they should be relatively self explanitory. There are a variety of ways to have the viewports layed out, which will be covered in the preferences section.
By default, you start with the top-down view, vertical view, camera view, texture window, and console.
Setting up Preferences
To change the window layout, press "P" or the Edit menu, then select Preferences. Once there, you can pick the style you want (See Fig. 2). It's most likely you will need to use the "top-down view" often, as well as some view that deals with the height.
Choose whichever layout you are most confortable with. To choose which one to use, click on "layout" underneath the "interface" menu (See Fig. 2). As you can see, the 3rd box is checked, which would give three 2D views and a camera (3D) view.
Most of the settings are self-explanatory but all of them are well detailed in the Gtk Radiant manual, the shortcut to it is located under the Help menu. Additionally Gtk Radiant includes manuals for some game packs, and when installed the one appropriate for the game you're editing for will also show up in the menu.
You should now have Radiant, q3map(2) and your views set up how you want, and are ready to begin mapping. You can move onto the Basic Construction Methods tutorial. Whether you have never mapped before, or have mapped in another editor but don't know what to do simply because key presses etc. are different than in say UTed or Worldcraft, the tutorials here should help you get familiar with the tools. You might think your too advanced to read this but its better to read how to map correctly at this stage rather than using previous experience which might differ and cause you some problems in the future.