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

ss_map mapname

Load mapname in splitscreen 2-player mode. Analogous to map in singleplayer. Like map, it is not required to add the trailing .bsp.

ss_splitmode mode

Changes the splitscreen mode.

ss_splitmode 0: Use recommended settings based on width

ss_splitmode 1: Top-and-bottom split

ss_splitmode 2: Side-by-side split

Dual Monitors

If you run dual monitors and want to split to each monitor, follow this guide

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.

in_forceuser

in_forceuser playerindex

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".

Note:If you are moving, crouching, shooting portals or otherwise performing an action when you change players, you will stop during the change but immediately resume the action when you change back. For instance, if you're holding "w" to move forward, you will stop moving forward as soon as you hit "z" (assuming you use the BindToggle above), but immediately resume moving forward when you hit "z" again even if "w" is no longer being held down. To stop this, simply tap "w" again, or use a more robust keybinding: Bind "z" "-moveleft; -moveright; -use; -forward; -back; -attack; -attack2; toggle in_forceuser".

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 Steam forums.

change_portalgun_linkage

This doesn't truly let you play the second character, but it does allow you to create more than one set of linked portals.

Todo: 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.

change_portalgun_linkage team

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

Todo: 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.

Other useful console commands

cmd2 command

Executes command as if typed by the second player.

cmd2 name Player2: Sets the name of the second player

ss_force_primary_fullscreen enable

Makes the first player fullscreen if enable is 1, hiding the second player's view.

There doesn't appear to be a way to do this with the second player, nor does holding Tab to show partner view (+remote_view) work.

See also

• Portal 2 Level Creation

External links

• Original version of this guide hosted at ThinkingWithPortals.com
• How-to: Split Screen Coop
• How-to: SplitScreen with 2 monitors
• How-to: Play Co_Op Alone