From Valve Developer Community

After the SteamPipe update in 2013, Half-Life Source now installs in Half-Life 2's directory. However, a Hammer configuration does not ship, nor does an FGD file. Half-Life Source.fgd is required for this process.

Game Configurations

Launch Hammer. Hammer will be installed with Half-Life 2, and can be found at common\Half-Life 2\bin\hammer.exe . Click on Tools, Options... to open the configuration window. Go to the tab labeled Game Configurations.

Configuration

Hammer allows you to setup multiple configurations, so if you want to make maps for more than one game, you can make maps for each on the same editor. This section allows you to add, remove, or edit different configurations.

Click Edit (the wide one at the top, not the smaller one below), Add, and name your configuration whatever you want. Click OK, Close.

Game Data Files

Note: halflifesource.fgd in common\Half-Life 2\bin . Copy the text from Half-Life Source.fgd into a Notepad document, save it asin

Click Add. Select the file at common\Half-Life 2\bin . You can select and use extra FGDs, but anything in them not coded to work in Half-Life: Source will not work. For example: HL2 entities.

Note: ALL filepaths you enter for configurations need to be absolute, meaning they start with the drive letter Steam is installed on and include the full path to the folder or file.

The Texture Format option should now say Materials (Half-Life 2) and the Map Type option should now say Half-Life 2. These should be the only options listed for either.

Default PointEntity class

The FGD tells Hammer to automatically select ai_ally_manager from the entity list when using the Entity Tool. You can change the default to any valid point entity you want.

Default SolidEntity class

The FGD tells Hammer to automatically select color_correction_volume from the entity list when you tie a brush to an entity. You can change the default to any valid brush entity you want.

Cordon texture

Set this to tools\toolsskybox . An alternative is BLACK .

Game Executable Directory

This is the folder containing hl2.exe. Select the folder common\Half-Life 2 .

Game Directory

This is the folder holding game-specific files, such as models, animations, textures, etc. For Half-Life: Source, this is at common\Half-Life 2\hl1 .

VMF Directory

This is where Hammer will save all files related to your map every time you compile. The engine looks in common\Half-Life 2\[your game folder]\maps for maps, however, Hammer will generate quite a few files related to your map when saving or compiling, so you may find it preferable to have a separate folder to contain them all (usually named mapsrc ). Compiled map files can be stored in another folder, which we will get to configuring near the end.

Build Programs

Now go to the tab labeled Build Programs. These are the programs that process your level geometry, determine where to optimize for visibility, and add lighting to your map. Many mappers use fan made modifications of the original tools developed for Source containing many fixes and improvements. If you use those tools, you will have to give filepaths for those instead of the ones talked about below.

Game Executable

A .exe file to open when the map finishes compiling. Unless you have some non-gaming purpose for Hammer, this should probably be common\Half-Life 2\hl2.exe .

BSP executable

BSP generates visleafs. This is at common\Half-Life 2\bin\vbsp.exe .

VIS executable

VIS determines what is visible from within each visleaf, which is used to save RAM for computers. This is at common\Half-Life 2\bin\vvis.exe .

RAD executable

RAD adds unchanging and toggleable lighting into your map, so it won't look so flat and boring. Dynamic lighting, like the HEV flashlight, is done directly in the game. This is at common\Half-Life 2\bin\vrad.exe .

Compiled Map Directory