Aperture Science Handheld Portal Device

"Thanks to the Aperture Science Handheld Portal Device, the impossible is easy."

- GLaDOS[src]

The Aperture Science Handheld Portal Device, also known as the Quantum Tunneling Device, Portal Gun, or by its acronym, "ASHPD", is an experimental tool used to create two portals through which objects can pass. The central piece of the "Portal project", Tier 3 of the three-tier program created by Aperture Science's CEO Cave Johnson on his deathbed in 1976, it is used within the Enrichment Center's Test Chambers as the Test Subjects' primary tool to complete each chamber.

Overview
The ASHPD is hand-held device which has the ability to manufacture two linked portals. No matter the distance between them, any object which passes through one portal will emerge from the other and vice versa instantaneously. The portals can be placed on almost any surface which is flat, immobile, and large enough to accommodate them. Moving objects, or certain types of surfaces, will prevent the formation of a portal. Material Emancipation Grids will block any attempt to shoot portals through them, as well as reset any active portals should the ASHPD pass through it.

The ASHPD is held with a hand behind the weapon, holding the handle / trigger, while the other hand supports the barrel. A sprite in the small hole on the top of the ASHPD and a sprite in its glass tube have the color of the last shot portal. It has two triggers, one for each of its two portals.

When the ASHPD is fired, a burst of colored energy is emitted from the barrel, corresponding to the colored portal it is intended to create. Upon striking the targeted surface, a portal is formed, surrounded by a colored ring. If the surface cannot accommodate a portal for whatever reason, the shot will dissipate in a shower of colored particles. If one portal is shot into its opposite, the portal will be formed next to the first one, assuming the surface has enough room for it to form; otherwise, it will dissipate as normal. The device can only create two portals at a time. If a third is fired, the other of its type will be automatically closed and a new link will be formed.

The portals fired by the ASHPD each have a distinct color. Chell's ASHPD uses light blue and light orange portals. ATLAS and P-body each use a variant on those two colors; ATLAS uses light blue and indigo (dark blue) portals, while P-body uses light orange and red portals.

Like the Gravity Gun, the ASHPD appears to featured a zero-point energy field, allowing Chell to pick up objects. However one has to stand close to the object to do so, and it cannot be thrown, suggesting the ASHPD has a weaker field. They can be carried through a portal, a process often required during tests. Unlike the Gravity Gun, however, High Energy Pellets, the Aperture Science equivalent of the Combine Energy Ball, cannot be picked up, either due to their instability or a weaker energy field.

Appearances
During Portal, Chell first acquires the ASHPD in Test Chamber 02; it fires only blue portals. It is later upgraded in Test Chamber 11 to fire the orange portals as well (while another model is found there, it actually consists of an upgrade to the current model, as said by GLaDOS). When each of the two versions of the gun are found, they are seen placed on a pedestal in the middle of a Test Chamber. The pedestal is constantly turning on itself, and the ASHPD shoots a portal each time it faces one of the four walls of the room it is in. Chell has to use the non-player controlled gun to complete the Test Chambers and once done acquires the initial ASHPD and later its upgrade. Currently it is not known how the two single ASHPDs are combined into one to result in a "modified" single gun.

In Portal 2, ATLAS and P-body are provided with fully-functional ASHPDs at the start of their testing.

Tactics


The ASHPD cannot create portals on every surface. While it can do so on any concrete surface, it will not work on certain tiled floors, metal, any kind of prop, doors or windows. However, it will work on security cameras, detaching them and making them fall on the ground. When shooting a portal on an unauthorized surface, the weapon's ray will bounce off and be turned into blue or orange particles that shortly disappear. This constraint was added to make puzzles deeper than merely teleporting to the exit.

With the noted exception of cameras, a portal is incapable of causing physical damage to either humans or objects. If a portal is closed while something is between it and the destination, the object will automatically be pushed out of one or the other, depending on which one the object is closer to. There are a few instances where the player can use portals to kill themselves, but this is likely an unintentional oversight.

The oval-shaped crosshair/reticle of the ASHPD indicates useful information pertaining to the portals. It first starts with a completely blue crosshair, as the first acquired ASHPD can only shoot blue portals. Later, when the ASHPD is upgraded to shoot orange portals, the crosshair is cut in two parts, blue and orange. Furthermore, a smaller oval appears next to the side that has been most recently fired. Finally, when the ASHPD is held in front of a surface where portals cannot be shot, only the outlines of the two oval elements are seen. A filled-in outline indicates a suitable surface.

Shooting an orange portal on an existing blue portal (or vice versa) will create the portal right next to it, if the room available allows it.

An Aperture Science Material Emancipation Grid will "reboot" any portal created by the ASHPD. In this way, the Test Subject starts each new Test Chamber with a "clean" portal network, and must use their assets properly to complete the chamber. They also appear within several chambers, forcing the Test Subject to find a way to work around them to complete an otherwise simple task.

Several portal creating techniques involving the ASHPD exist to complete several Test Chambers. They are covered in great detail in the Portal Prima Guide.

The various Test Chambers require the use of several portal creating techniques, where the ASHPD and momentum play a pivotal part:


 * The most basic technique is "Flinging", whereby one transforms downward momentum into forward momentum by means of cleverly placed portals. This is mainly used to clear large gaps or obstacles when more orthodox means, such as stairs or lifts, are not available. The concept simply requires to place one portal facing outward on a high wall across from the area that one wishes to fly over. Meanwhile, the second portal is placed in a nearby pit. By jumping into the pit portal, the momentum will "fling" the user through the wall portal and to their destination. A slight variant to this is the "Wedge Fling," where the wall-based portal is instead placed on a upward-slanted, elevated surface for vertical travel as opposed to horizontal travel.


 * A more complex form of "Flinging" is the "Double Fling", performed when lacking a deep enough pit from which to fling. It is performed in the same manner as flinging, but at a reduced height. In the absence of a pit or tall object to jump from, one portal is placed on the floor instead, while the other is placed on the wall as before. Entering into the floor portal will eject the player from the wall portal. As the player falls, they should move the floor portal below them (if necessary) to "catch" themselves. This portal will fling them through the wall portal with their momentum intact, thereby gaining the needed momentum without the use of a pit.


 * In the absence of a portal-friendly high wall from which to fling, there is another way to exploit momentum for the purposes of reaching remote ledges: the "Floor-to-Floor" technique. Instead of placing one portal on a high wall, it is instead placed on the floor while the second is placed in a pit. Jumping into the pit ejects the player from the ground-level portal, allowing them to reach a previously unattainable ledge.


 * The last technique, advised to be mastered by the player who wants to succeed in the Advanced Chambers, is called "Portal Ledge". It involves standing partway through an already deployed portal, and using it as a ledge to reach surfaces beyond the range of the current location. It can literally be used as a ledge to jump through, or another portal can be created from inside it and edge one's way toward a distant destination. The latter technique requires the player to exit out of their original portal immediately after placing the second portal, to prevent them from exiting through it. Creatively utilized in this way, the Portal Ledge enables the player to skip large parts of rooms.

Behind the scenes



 * The concept of shooting blue and orange portals to solve puzzles was directly imported from Narbacular Drop, whose team was hired by Valve to develop that technology into what became Portal.


 * The earliest known ASHPD model appeared like a modified Gravity Gun. The prongs directly based on that of the latter are still in the final model.


 * The ASHPD model seen in the Portal trailer features "F-22" written in black on its top, while concept art shows "A-12". It was replaced in the final model by the word "APERTURE" with under it a barcode and "04/". The end is faded, suggesting more alphanumerics used to come after "04/". This number suggests that the gun used by Chell is model 4 among the gun reserve, or that this model is the fourth version of the gun.


 * As seen in a very early Portal screenshot, the hands and forearms of the ASHPD user were to be featured in the viewmodel. Chell's right hand and forearm are still present in the final viewmodel, although the texture is broken. However the texture file can still be found in the game files, revealing what may be an early Aperture Science logo, followed by the number "122-7605", possibly an early Test Subject ID. These are not featured in Chell's model, which probably did not (at least fully) exist at that time of the game's development.




 * As seen in several early Portal screenshots, a modified Half-Life 2 HUD was first reused.


 * As seen in the earliest known Portal screenshot, the orange portal was originally purple. The final colors, blue and orange, are actually the same as the ones featured in Narbacular Drop, Portal’s predecessor technically speaking. Before being orange, the orange portal also was more halfway between yellow and orange.


 * The portals seen in the Portal trailer are slightly different than the retail ones, and have purple waves swirling in the middle.


 * The firing sound of the ASHPD when it is still attached to its pedestal originally was the charging sound of the Combine Guard Gun, a weapon cut from Half-Life 2.


 * The "ASHPD" acronym bears a striking resemblance to Adrian Shephard's name (Adrian SHePharD), which led many players to speculate it is a hidden Easter egg, suggesting Shephard's involvement in Portal or its sequel. In addition, completing Portal unlocks a new menu background which contains a keyboard that has all the letters in Adrian Shephard's name highlighted, and these keyboards can also be seen throughout the game. Kim Swift said in an interview that the ASHPD acronym was actually a complete coincidence and that they added the keyboard highlights after people mentioned the acronym. Valve's Doug Lombardi subsequently confirmed the Portal reference as a complete coincidence.


 * The ASHPD in Portal 2 will apparently have new firing sounds, as well as new sounds when something goes through a portal. The portals are also expected to give off light in their surroundings.


 * As shown in the TrueMotion Portal 2 demonstration with the Sixaxis controller for PC, the ASHPD seems to have new abilities, similar to the Physics Gun from Half-Life 2 Beta. In addition to its normal ability to pick up objects, it can extend the beam to move them over great distances, even through portals. It can also physically grab and reorient portals, presumably as long as they remain attached to an acceptable surface. Solid objects grabbed by the beam can be rotated on all three axises, allowing for precision aiming with the Weighted Pivot Cube. There is also a new type of Cube which can be manipulated by the ASHPD, allowing the user to make it larger and distort its shape. Doing so also changes the physical properties of the cube; making the cube larger for example, not only increases its size but also its mass, allowing it to break a pane of glass that it normally could not. These features will only be available for those with the Sixaxis controller as a extra content pack.

Trivia

 * Only one of the Portal Achievements is directly related to the ASHPD. Named "Lab Rat", it simply requires to acquire the fully powered ASHPD in Test Chamber 11.


 * Typing "impulse 101" in Portal gives all the Half-Life 2 weapons and shows the HUD, where a standing man glyph is used for the ASHPD.


 * The ASHPD does not work be default in Garry's Mod. Although its prop can be imported with the Portal content, it cannot be spawned as as working portal device, as Garry's Mod does not have the necessary code to make it work. However fan-made working versions are available.


 * The ASHPD can be used in Half-Life 2 and its episodes and Half-Life: Source by simply copying all the game data of the related game into the Portal data folder, then using the console to load the required map. The Half-Life 2 maps will work seamlessly with the ASHPD and vice versa, partly because of development and system similarity.


 * When Chell is killed by an Energy Pellet, the ASHPD disintegrates with her.


 * In Portal 2, the Portal Gun now has a walking animation as evident in the video shown by Valve.


 * In the Portal 2: Valentine's Day, the Portal Device has the portal firing sounds switched over (blue to orange and orange to blue).


 * According to the Aperture Investment Opportunity #4: Boots video, the ASHPD is powered by a miniature black hole, which is kept stable through the use of a cooling fan at the rear of the device. In case the black hole should begin to fail, two miniature German stick grenades, stored within the casing, can be used to restart it. Should the fan fail, the device should be disassembled to retrieve the Event Horizon Estimation Wheel, which will determine the minimum safe distance to survive the resulting overload.

List of appearances

 * Portal
 * Portal: First Slice
 * Portal: Still Alive
 * Portal ARG
 * Portal 2: Lab Rat
 * Portal 2