Before starting, you should learn a little more about the structure of the resources that Hammer and Half Life can use in a game. The Half Life engine can access and use a wide variety of file types and other resources. The list below is arranged by resource type, and each resource type includes a list of the sorts of files Half Life can use in that type, as well as a description of those files.
As mentioned before, the project is the total of your whole game and all its resources. An .RMF (Hammer Project) file at the top of your tree of game resource directories serves as a guide to Hammer. The .RMF file is a pointer to the rest of the resources for hammer and includes some of the information about your game resources. The rest of your games files exist in sub directories of the directory where your mod resides.
The sub directories that Half Life use, are in your mods, folder, if you opened up your /half life /cstrike folder you would find allot of files, that you know not to remove, just in case you have to reinstall CS. Well each folder has different Resources in them. Sounds have all the sounds you hear in game, such as pressing c1
(Roger that) this wav file is in the /cstrike/sounds/radio folder, along with allot more sounds. The dog that barks in back ally, is in the folder /cstrike /sounds/ambience/. The m4a1 that you might like to hold, is in your hand is in the /cstrike /models folder, while the T that your going to shot with the m4a1 is in the /cstrike/models/player folder. The wad files, if your don 't understand them yet, are in the root mod folder, such as cs_dust, is the de_dust wad file, and that sits in the /cstrike folder.
Note: removing resource is not a wise idea, as this can cause you to have to reinstall CS. You can add folders for your map, if you use custom resources. Just make shore that you package your folders, and custom resources in your .zip when you make them public.
Come in two forms .RMF files and .BSP files. If you think of worlds as programs, the .RMF file is the source code: Editable and understandable by the user and hammer, but not executable. The .BSP file is like an actual program: it can be run in the game, but since it’s been “compiled” (processed, in this case), the user can no longer modify it. The .RMF files are what you change and save changes to inside of hammer, and the .BSP file is the output of the ZHLT Compile Tools, which prepares your world to run in the game and optimises its performance.
Half Life uses its own form of texture, the .wad file. Textures can be up to 8 bit images, although you can obviously choose to make lower colour textures. The .wad files also contain flags for additional information used by the engine and the game. You can convert .BMP, and .JPG files into .wad files by using a program such as Wally http://home.telefragged.com/wally/
(.SPR files) consist of a series of .bmp files linked together as an animation with a set frame rate. They 're commonly used for animations and special effects such as smoke, or liquid droplets.
Half Life supports standard 8 bit mono .WAV files. You can convert high sound files, and the sound recorder 8 bit mono 's with gold wave http://www.goldwave.com/ a very useful program.
Half-Life Models are in a custom format, the .MDL file. This contains the mesh /geometry for the model and other information used by the game engine. You create these files in an external editor such as Maya or 3D Studio Max, then save them in the .MDL file format using a plug-in. You can also get your hands on a shareware program named milk shape from http://www.milkshape3d.com
Also known as Entities, these are objects that programmers construct using code. Some of this code exists in the engine and doesn’t 't appear in the entity lists. However, many objects are created in code written for the specific game. These objects are called game objects (to distinguish them from the engine objects inside the engine code) and are stored in a file called a Game Data File or .FGD.
A prefab is a collection of objects, both brushes and code objects that are stored in their own .OL files. Anything you make in a level can be exported as a prefab to make it easier to re-use later. Examples are benches, camera systems, hallways, doorways, and statues.