Throughout Portal's 2 years of development, the ending, and its boss, GLaDOS, was changed quite a number of times, going from a simple escape from an abandoned facility to a battle against a floating cube of rollermines before its final rendition of a giant feminine AI supercomputer. This page aims to explain and display all the known eras, screenshots, and other such information concerning GLaDOS and the escape throughout Portal 1's development, as well as her appearance in Portal's followups.
- 1 Version 0: Pre-GLaDOS / Nova Prospekt Era (lab_lvl3a)
- 2 Version 1: Laser Turret
- 3 Version 2: Rocket Turret
- 4 Version 3: Chase Sequence (escape_01)
- 5 Version 3.5: Chase Sequence (escape_02)
- 6 Concept
- 7 Version 4: Central AI Chamber (proto_escape/styleguide_escape_02)
- 8 Version 5: Final
Version 0: Pre-GLaDOS / Nova Prospekt Era (lab_lvl3a)
Prior to the conceptualization of the Aperture Science Computer-Aided Enrichment Center, the story followed an unnamed test subject through a Nova Prospekt-esque facility. What is presumably the final level of this era of development, referred to as the "Prospekt Era," is found in the Portal 1 leaked mappack, titled "lab_lvl3a." This gauntlet of mini-challenges has the player going throughout the behind-the-scenes areas of the facility in order to locate 4 car batteries in order to restore the power to the facility and unlock the front door.
Lab_lvl3a contains the most Prospekt-era content of any leaked map due to it being an actual full map from the era. With this, the map file contains portions of 3 separate era chambers, chambers 0, 13, and 18, as well as the nomenclature for said chambers. What is interesting about this, is that, although chambers 0 and 13 use logically sound names (intro_lvl and intro_lvl7,) Chamber 18 is an outlier and a conundrum in itself, having a name that would place it past this level (lab_lvl4.) There are a plethora of theories behind the reason for this name, ranging from that the map was conceptualized after the creation of lab_lvl3a to that lab_lvl3a wasn't actually the final escape map and that the exit would have looped back around. For the time being, however, there is no definitive evidence behind any of this, and, with how bizarre some map names for Prospekt-era Portal are, it may very well just be coincidental.
Version 1: Laser Turret
Following the creation of Aperture Science, the first rendition of GLaDOS involved the use of the cut "Laser turrets" (later turned into the rocket turrets.) This fight saw temp GLaDOS as a cube made out of refracting glass being powered by 4 generator plugs. The player would need to redirect lasers from the laser turrets into these plugs in order to destroy them, thus killing GLaDOS in the process. This rendition was found to be too boring for testers.
- Although for years, there were only 2 images of this fight, in low quality, a third was recently found, as well as full resolution versions of the original two images, in Portal's Postmortem GDC showcase.
- Although Laser turrets were replaced outright by rocket turrets, some functions of their abilities still exist, especially including the ability to redirect env_laser entities through portals. Said entities can also be used to destroy turrets much in the same way as Portal 2.
Version 2: Rocket Turret
The second rendition of GLaDOS saw a slight redesign as a cube made up of rollermines as opposed to glass. This fight with her was amped up as a complex brawl with her "brain" which would move around while the player was attempting to redirect missiles at it. Pillboxes would also open up at random intervals around the arena with turrets on the inside. This version was scrapped due to being too action-oriented, as players would ignore GLaDOS as she was rising up in the room in order to pay attention to the turrets opening up in the surrounding pillboxes.
- This is the first version of the GLaDOS fight to introduce the Pillbox room, a room that made it into the final game.
- Leftovers for the randomly opening Pillboxes are found on the 2006 vmf of Escape_01, proving that the GLaDOS fight was initially found on this map before being moved to its own.
Version 3: Chase Sequence (escape_01)
The third version of GLaDOS was built upon the second version, and includes much of the same elements. The defining difference between these versions is that, while Version 2 was exclusive to the Pillbox room, Version 3 includes a chase sequence and a final confrontation. There are two separate versions of the V3 GLaDOS fight, one of which can be found in the 2006 vmfs without any necessary modifications, and the other being found within an unused visgroup of the 2006 version of escape_01, titled "steaming refuse." This version of the V3 fight starts out the same as its later version, but, as opposed to the long chase sequence found in the leaked version, the chase sequence in steaming refuse is much shorter, and, as opposed to GLaDOS only taking 3 hits in the leaked version, she takes 4 in this. The level ends with a wall breaking open allowing the player to leave the facility through a Portal. Although the level is split up and cannot be played normally, a recreation can be found here.
- Steaming Refuse has leftovers of the laser turret before it was redesigned.
- Interestingly enough, nomenclature refers to the turrets both as laser AND rocket turrets. The reason for this inconsistent nomenclature is unknown.
- The room that the player escapes into is seen on several other test maps.
- The level contains a 3d skybox that cannot be seen normally. This is likely because the skybox overlaps with several visleafs for earlier parts of the map and appears awkward at most angles.
Version 3.5: Chase Sequence (escape_02)
This rendition of the GLaDOS fight is found inside the 2006 leak vmf folder, being the 2006 version of "Escape_02." The start of this fight is very similar to its previous rendition, with the divergence taking place in the chase sequence. Whereas the Steaming Refuse version of the fight has a relatively short chase sequence, the leak version is incredibly long and features an entirely new room at the end filled with even more turrets. The reason for Version 3 being cut is due to its poor pacing, necessity for a large number of new art assets, and poorly balanced gameplay.
- The cubby that GLaDOS hides in in the final room uses model materials, which will not load properly in hammer unless a modified version is used.
- The old 3d skybox from the steaming refuse version is left in this map, being far away from where the actual exit is.
- The map logic for GLaDOS taking 4 hits of damage is still in the vmf, but the final hit executes the logic for hits 3 and 4 at the same time.
- The Portal GDC Postmortem showcases screenshots of a slightly different version of the map than the one found in the leak.
Although the concept of a machine looking down from the ceiling was almost always present for GLaDOS, what her body would look like changed a number of times. Here is her concept art:
Version 4: Central AI Chamber (proto_escape/styleguide_escape_02)
This rendition of GLaDOS is almost identical to her final form, with the differences being mostly a matter of details and minor balancing. Because Proto_Escape and Styleguide_escape_02 are nearly identical to one another, they will be marked as a single version for the sake of time for this article.
- There are both brush and model visgroups in these maps for GLaDOS' generator.
- Said Generator once used a single model for the spinning parts as opposed to 4 separate models. This was changed in the final so that the different rotating generator parts can have slightly different sizes to one another.
- The rocket turret is in a different location to retail.
- One of the few noticeable differences between Proto_escape and styleguide_escape_02 are that the styleguide version contains a window on the incinerator. Interestingly, this is not present in the vmf, meaning that it is likely a compile error.
- Despite the fact that the desks have not been implemented, there is still a table with the emergency phone, showcasing how important it was as a plotpoint to the developers. In the final game, this plot point is only mentioned in the dev commentary.
- All of the cores except for the anger core were finalized at this point. In both versions of the map, the anger core is not present, instead using another morality core.
- Interestingly, all cores on GLaDOS are morality cores until being knocked off.
- GLaDOS is a static prop in these maps. This was changed in the final so that she could swing around and attempt to dodge the oncoming rockets.
Version 5: Final
This is the GLaDOS that shipped with the final product. Other than additional dialogue, models in place of their brush counter parts, and an ending sequence, she is nearly identical to her previous counterpart.
- The rocket turret has been moved from its original location
- The final core is now the anger core
- GLaDOS shakes around during the later portion of the fight, making it slightly more difficult to aim rockets at her.