Hub

The Hub is a section of Aperture Science that is featured exclusively during the Cooperative Testing Initiative. Through the Computer Intelligence Training and Enrichment Center Human Test Subject Research Center, or CinTech (pronounced Sin-Tech), Atlas and P-Body can access the various test chambers that are featured throughout the coop campaign.

It features a large screen that displays the total steps players have taken since starting co-op, as well as total portals fired and other statistics. Additionally, it has Aerial Faith Plates, Hard Light Bridges, and Panels that allow for easy traversal of the chamber.

Trivia

 * There are 3 different map files for hub.
 * As the host (Atlas/player 1), to reset your progress so that your testing partner can experience the story in the Hub from the beginning, use the console to enter in mp_mark_all_maps_incomplete. You won't lose your achievements or your accumulated stats (portals placed, footsteps taken, etc.), but after resetting the level with, all of the test chambers will be closed off and you'll hear GLaDOS's lines again. If your friend was further along with some of the sections done, you can use mp_mark_course_complete and then 0, 1, 2, or 3, depending on what their last completed section was, to make your completion progress roughly equal. Finally, use changelevel again to load the map with the changes applied.
 * As the host (Atlas/player 1), to reset your progress so that your testing partner can experience the story in the Hub from the beginning, use the console to enter in mp_mark_all_maps_incomplete. You won't lose your achievements or your accumulated stats (portals placed, footsteps taken, etc.), but after resetting the level with, all of the test chambers will be closed off and you'll hear GLaDOS's lines again. If your friend was further along with some of the sections done, you can use mp_mark_course_complete and then 0, 1, 2, or 3, depending on what their last completed section was, to make your completion progress roughly equal. Finally, use changelevel again to load the map with the changes applied.
 * As the host (Atlas/player 1), to reset your progress so that your testing partner can experience the story in the Hub from the beginning, use the console to enter in mp_mark_all_maps_incomplete. You won't lose your achievements or your accumulated stats (portals placed, footsteps taken, etc.), but after resetting the level with, all of the test chambers will be closed off and you'll hear GLaDOS's lines again. If your friend was further along with some of the sections done, you can use mp_mark_course_complete and then 0, 1, 2, or 3, depending on what their last completed section was, to make your completion progress roughly equal. Finally, use changelevel again to load the map with the changes applied.
 * As the host (Atlas/player 1), to reset your progress so that your testing partner can experience the story in the Hub from the beginning, use the console to enter in mp_mark_all_maps_incomplete. You won't lose your achievements or your accumulated stats (portals placed, footsteps taken, etc.), but after resetting the level with, all of the test chambers will be closed off and you'll hear GLaDOS's lines again. If your friend was further along with some of the sections done, you can use mp_mark_course_complete and then 0, 1, 2, or 3, depending on what their last completed section was, to make your completion progress roughly equal. Finally, use changelevel again to load the map with the changes applied.