Before you start, you should know that maps with simple geometry work best for porting. Complex geometry can cause invalid solids which will need to be manually remade, and some textures will need to be realigned.
- Have a basic understanding of Goldsrc, Valve Hammer Editor, and potentially Trenchbroom
Download the .BSP and (in some cases) the .WAD
You can download maps from Xtreme-Jumps or by joining an Adrenaline Gamer Kreedz server, and switching the map with
agmap. The BSP is the actual map file, and the WAD contains the textures used in the map, although in most cases custom textures will be embedded into the BSP.
Obtaining the .map file
You will need the .map/.rmf/.jmf file for the map you wish to port to Source. It will make your life much easier if you can get the original from the creator, however it is not required.
What decompiler to use?
Both are pretty bad. Goldsrc doesn’t store original brush geometry in its BSPs like Source does. WinBSPC decompiles the map by carving it out of a large box the size of the map. As such, while the geometry is usually workable in-game, it’s very hard to edit should you want to make any changes. BSPTwoMap on the other hand, directly spits out the polygons in the map, converted into brushes. As such, a box would instead of taking one brush, use 5 or 6. This can be fixed by opening Trenchbroom and manually combining all the brushes. While it is a long process, it results in much better geometry that is easier to edit. Another bonus of BSPTwoMap is that it automatically extracts embedded textures in the map into a .WAD.
Decompiling with WinBSPC
Open WinBSPC, in the top left corner select file > convert. Navigate to the BSP file you wish to decompile and select it. Choose Convert to: MAP, and best match texturing. Choose the desired output folder and click OK.
Decompiling with BSPTwoMap
BSPTwoMap, is a command-line application, simply drag the bsp onto to .exe to decompile it.
Converting the textures
Some maps don’t embed textures and simply come with a .WAD however most do not. As mentioned earlier, BSPTwoMap will extract them on decompile, it’s recommended to simply decompile the BSP again with BSPTwoMap to get the .WAD even if you’re using WinBSPC. Once you’ve obtained the .WAD, you need to convert it to Source materials. This is done with a program called xwad. Xwad is a command line application, you can get it by downloading the Source SDK on steam, (NOT 2007 or 2013) and navigating the bin folder where the developer tools are stored. You’ll need to create a .bat and add the parameters -BaseDir (location of the momentum folder) -WadFile (location of the .wad) and -vtex (automatically calls vtex to convert the created TGA files into VTF files). The .bat would look a little something like this:
xwad -BaseDir [PATH TO MOMENTUM FOLDER] -WadFile [PATH TO .WAD] -vtex
The resulting folders should be placed in the materials folder of the game you are mapping for. Any still missing textures would be from Half-Life, TFC, or Counter-Strike, do the same process for those WADs.
If using BSPTwoMap
Download Trenchbroom set it up for Half-Life(experimental). Open the map with J.A.C.K (see below) remove and then fix the invalid brushes. You will need to do it in J.A.C.K and not Hammer. Then, open the .map and go around combining mutiple brushes that would be one single brush by control-clicking them all, and press control+j (convex merge). This will take a long time if it’s a large and complex map.
Converting .map to .vmf
Download J.A.C.K and install it. You do not need to fill out the install locations of games that J.A.C.K. can use during the install process if you do not own any of the games, it will still be able to convert the files without it.
Once it is installed, open J.A.C.K. and click Tools > Options, or press F2 to bring up the settings. In the Game Profiles tab, make sure that the map type is set to Half-Life / TFC before trying to open the .map file, otherwise the map may fail to load.
Now click File > Open, and open the .map file you are converting. Once it has loaded, there will likely be invalid solids that stretch to infinity. Delete these now, you’ll need to remake them later. Click File > Save As… and save as a “Half-Life VMF”.
Before you open this VMF in Hammer however, there’s one more thing we should do. Download a tool called GoldSrc2Source. Click Find VMF and navigate the VMF file you just saved in J.A.C.K. Select it and click repair, it’s best to have all parameters marked in GoldSrc2Source in the vast majority of cases.
Finally, load Hammer and open the VMF! There will likely be a few missing textures through the map, but these will be tool textures. Find them and replace them to their Source equivalent.
Now you can start converting the entities to their Source equivalents. The trigger_multiple entities that are used for controlling the timer should be converted to the momentum mod zone system;
Now it’s time to put the final polish on the map. Fix up any broken geometry (although there might not be any if the map is simple enough), fix the lighting issues if there are any, and align any textures that may have become misaligned. You also might have to func_detail some of the brushes if there are a lot of small details, in order to cut down compile times.
You can now compile the map!