Testing Portal 2 Co-Op Maps Alone
This is a guide on how you can test co-op maps alone utilizing the splitscreen capabilities of the Source engine. This also works for any existing coop maps. It does not require any modifications to the map file itself.
This does not cover the requirements for making a coop level in the first place.
Loading the Map
mapnamein splitscreen 2-player mode. Analogous to map in singleplayer. Like map, it is not required to add the trailing .bsp.
- Changes the splitscreen mode.
ss_splitmode 0: Side-by-side split
ss_splitmode 1: Top-and-bottom split
If you run dual monitors and want to split to each monitor, follow [this guide|http://forums.steampowered.com/forums/showthread.php?t=1857198]
Controlling the second player
If you could actually play the coop map entirely as one player, it wouldn't be a very cooperative map. These are some ways you can control the second player.
- Take over the second player. All movement and other keybindings will be as if the second player used them. Requires cheats to be enabled.
sv_cheats 1: Turn on cheats
in_forceuser 0: Control player #1 (Atlas)
in_forceuser 1: Control player #2 (P-Body)
To make this easy to use, set a keybinding for it:
BindToggle "z" in_forceuser
- Swaps you between first and second player when you push "z".
Use a controller
This is actually more complicated than it sounds unless you have two controllers available. Source will map actions of the first detected controller to the first player and there doesn't seem to be away to override this. The workaround is to either have two actual controllers or use trickery to make your computer think it has two controllers.
More information for this can be found on the [forums]
This doesn't truly let you play the second character, but it does allow you to create more than one set of linked portals.
To do: It's not yet tested to see if portals that are in the set you aren't currently linked to survive going through a fizzler.
- Changes portals fired to belong to the specified team.
change_portalgun_linkage 0: Chell
change_portalgun_linkage 1: Unknown
change_portalgun_linkage 2: Atlas
change_portalgun_linkage 3: P-Body
- To do: Verify that these values are correct.
Note that the color of portals fired will be unchanged -- Atlas will shoot blue and purple portals regardless of the setting of change_portalgun_linkage.
- Original version of this guide @ ThinkingWithPortals
- How-to: Split Screen Coop @ Steam Forums
- How-to: SplitScreen with 2 monitors @ Steam Forums
- How-to: Play Co_Op Alone @ Steam Forums
I recommend the first option -- it's the easiest to set up, and doesn't require you to jump back and forth between mouse+keyboard and controller.
Of course, if you really are testing with two people, the second option is probably your best bet.