Let's Play a Portal 2 Test Chamber (Part 1)

Although I've finished the single player campaign, I still wanting to play some co-op before I review Portal 2. I did comment before that the puzzles were generally on the easier side - to tide over those potentially interested in Portal 2, I'll do a play-by-play of one of the more interesting test chambers in the game. Hopefully you'll glean some insight into the puzzle-solving process or be inspired enough to buy the game.

SPOILERS! This post is naturally one big spoiler for one of the puzzles in Portal 2.

The basic mechanics of Portal 2 are very simple. You carry a gun which can shoot blue portals and orange portals. Shooting a blue portal will clear an existing blue portal; likewise shooting an orange portal clears an existing orange portal. The blue and orange portals are linked - anything passing through one portal will emerge from the other while retaining its existing momentum. These portals can only exist on smooth white surfaces. Test chambers typically have plenty of such surfaces, while they are few and far between in other areas of Aperture Labs.

Overview of the test chamber

First thing we do when we enter the test chamber is identify where the exit is - marked E.

Next we identify all the useful environmental components to the test chamber:

1. Light funnel - this will force any objects caught in the funnel (including our character) directly along the funnel and away from the source, i.e. downward. However it is being directed onto a portal-appropriate surface which will allow us to continue the light funnel in many different places and in different directions. The yellow lighted line indicates that the light funnel is currently turned on because of something down in that pit. We'll have to take a closer look.
2. Box - always handy boxes are, we can carry this around if we can get up to that area.
3. Faith plate - a spring catapult. Closer inspection/experimentation reveals that it will launch us (or any object) at the surface marked T.
4. Elevator platform - follow the light blue line to the right to see what trigger will lower this platform.
5. Elevator platform - follow the light blue line to the left to see what trigger will lower this platform.

Ceiling button

Following the blue line to the left, the upper elevator platform (5) is shown to be controlled by a button on the ceiling. A button won't remain pressed unless you hold it pressed. Normally you can leave a box resting on it, but to keep a button pressed in the ceiling will require a constant force to hold a box up against it. There's only one thing that we've seen that can produce that force, and that's the light funnel. If we can get the box, we can easily send it up and keep it pressing the button.

Laser trigger

Following the other blue line to the right, the lower elevator platform (4) is shown to be controlled by a laser trigger. A laser has to be directed at the trigger to lower the platform. We just have to find a laser then.

Pit area

Inspecting the pit shows us the following components:

1. Laser - a laser source is directly a laser from left to right across the pit. Unfortunately we can't simply use portals to connect the laser up to the previously mentioned laser trigger because it's being projected onto a non-portal-accepting surface.
2. Laser trigger - this trigger controls the light funnel and is currently active.
3. Deflection box - like a normal box except this one can be used to deflect a laser in any horizontal direction. This box is also on a raised area that we can't simply jump to.

That's everything in the test chamber. Maybe you can figure it out before looking at part 2 in which I'll show you how I found a solution.