Created by gamedesk logo
Science > Physics

PORTAL 2 - EDUCATION VERSION

Put the mind-bending puzzle game Portal 2 to the test by creating and playing custom levels!

grade level:
6-12
profile avatar
Created by
Agustin Molfino
Curriculum Writer

Overview

The Portal 2 - Education Version is a custom modification of Portal 2, the critically acclaimed single-player puzzle game from the developers at Valve. This modified version of Portal 2, along with a game called Universe Sandbox, is part of a program Valve is calling Steam for Schools (not to be confused with the STEAM education movement that shares the same name), in which they hope to encourage teachers to use their games to teach standards-based curriculum.
Intro

Portal 2 - Education Version

Portal 2 is well known for its single-player story mode, but this is not the centerpiece of the Portal 2 -Education Version. The centerpiece of this modified version is the Puzzle Maker, a level-creation tool. The Puzzle Maker makes it so that players are no longer just solving but creating, sharing, and playing their puzzles or “test chambers.” Best of all, while making test chambers is easy and provides instant gratification, creating good levels is also intellectually challenging and provides endless opportunities for creative and critical thinking.

Intro_2

Creating levels in Portal 2

The Puzzle Maker in Portal 2 - Education Version includes functions and features to help teachers use it as an effective learning tool. These features include:

  • a stopwatch (See ‘Education Controls’)
  • the ability to slow time (See ‘Education Controls’)
  • the ability to manipulate objects’ physical properties (See the ‘Contraption cube’)
  • the ability to view objects’ physical properties (See ‘physics_debunk_entity’ console command)

Each puzzle or test chamber has a simple objective: unlock the exit door and get to it. Complicating this objective are a number of puzzle elements that need to be triggered (e.g. levers, buttons, platforms, faith plates, etc.) in order to reach the door and/or unlock it. For example, a player may have to find a cube and place it on a button to trigger a faith plate (a catapult), which the player will then use to launch over a gap onto the ledge where the exit door is located.

Figure2

Puzzle in Portal 2

While this is an example of a very easy puzzle, many of the puzzles in Portal 2 would be impossible if not for the game’s main feature: the portal gun. The portal gun allows players essentially to create wormholes between surfaces. Anything that enters one side of the portal(including the player) will exit out of the other. This becomes useful in a variety of situations, including, but not limited to, reaching seemingly unreachable ledges or areas, flinging oneself or objects across gaps, and redirecting lasers and other beams (how all of this works makes more sense after a few minutes of gameplay). 

The Portal 2 test chambers provide students with the opportunity to develop their critical and creative problem-solving skills. These skills are needed to solve room puzzles but are even better engaged by creating puzzles. Additionally, by building test chambers with the Puzzle Maker, students also participate in the iterative design, test, and redesign processes essential to game design.

Student learning is limited not just to critical thinking skills but also to academic content, since Portal 2 uses a game engine that mimics real world physics rather closely. This allows teachers to use the game to teach physics concepts like gravity, terminal velocity, conservation of momentum, and the associated math formulas. While the physics engine is consistent and fairly similar to the physical forces on earth, there are some peculiarities of note:

General 

  • The acceleration due to gravity is 4.7 u/s^2. One unit is one wall panel, and one wall panel is 2.4m. Therefore, the acceleration due to gravity in the game is 11.28 m/s^2, which is a bit more than acceleration due to gravity on Earth (9.8 m/s^2).

Portal-Related

  • All players and objects are subject to loss of momentum due to air friction EXCEPT for PLAYERS exiting a portal. Thus, only players exiting a portal conserve 100% of their momentum.
  • Portals have a limit to how fast objects or layers can go through them (a terminal velocity). That limit is  7.8 u/s (18.72 m/s), meaning that any object or player going faster than that is automatically slowed down to 7.8 u/s.
  • Portals have a dampening limit. There is a minimum amplitude of oscillations through portals, meaning objects oscillating through portals will never completely stop. 

While some might see these differences as limitations, they actually provide an opportunity for students to test the accuracy of Portal 2’s physics engine and then discuss and identify possible reasons for the differences. For example, the fact that players going through portals do not lose momentum (due to air friction), while objects do, provides a perfect opportunity to compare how momentum is conserved with and without air friction. It also leads to a game-design discussion of why the game developers chose not to limit players’ momentum through portals.

PORTAL 2 - EDUCATION VERSION Breakdown

Ease of Use

Portal for Education requires players to learn two interfaces:

  • The in-game interface is exactly like a first-person shooter (with the added quirky functions that the portal gun provides); thus it is easily graspable for those already familiar with the genre. For others, there will be a learning curve.
  • The creation mode interface in the Puzzle Maker takes no more than 10 minutes to understand at a basic level, but to know what puzzle pieces do and how to apply them correctly requires some experience playing the game (either in other test chambers or in the single-player game). Actually creating a level that is unique and challenging requires a significant time investment.

Mechanics

Portal 2 is a first-person shooter focused on spatial awareness and puzzle solving. Instead of a typical gun, the player has a portal gun that doesn’t shoot bullets but shoots two types of portals, blue and orange. The player can enter one of the portals and exit the other, completely transforming where and how they move in space.

At the start of each level, the player is introduced to a test room and must reach the exit door by reasoning through a series of triggers and puzzle elements, using the spatial navigation enabled by the portal gun and its portals.

Game Controls

These are the default controls. They can be modified in Option >Keyboard/Mouse >Edit Keys/Buttons.

Movement

Movement
Jump
Duck

Key/Button

Standard WASD
SPACE
CTRL

Actions

Fire Blue Portal
Fire Orange Portal
Use Items

Key/Button

Left Click
Right Click
E

Miscellaneous

Take a screenshot
Toggle Developer Console

Key/Button

F12
~ (tilda)

Education

Start timer
Stop timer
Reset timer
Start/Stop timer
Objects move at:
100% speed
0% speed
50% speed
10% speed
1% speed

Key/Button

J
K
L
O

1
2
3
4
5
  • Note: Toggle Developer Console (~) opens a window that allows the user to enter “console commands.” Console commands are small lines of simple code that, when entered in the developer console window, give players many more options for altering the game room and the game experience. It is recommended that players (especially teachers) understand and use these commands.
To use console commands, follow these steps:

Step 1 In the main menu, go to Options > Keyboard/Mouse. Enable 'Allow Developer Console.'

Step 2 When in a test chamber (in game) press ~ (upper left of the keyboard). This window will appear:

Figure5

Console Commands

Step 3 To enable a host of useful console commands enter the command sv_cheats 1. To disable them, enter the code sv_cheats 0. Note: some command codes will work without the need to turn on cheats.

Step 4 Useful tip: the command code bind ‘key’ ‘command’ will link that console command to a keyboard key, liberating the player from having to enter the code in the console window every time (e.g. bind ‘7’ ‘noclip’ will make it so that pressing ‘7’ turns on and off ‘noclip’ function while in the game). 

A list of useful command codes and their functions follows (not exhaustive):

Command

noclip

impulse 2000

give_portalgun

upgrade_potatogun

impulse 1000

sv_portal_placement_never_fail 1

portals_resizeall w h

firstperson

thirdperson

god

physics_debunk_entity

Result

Gives player ability to fly and go through walls

Removes portal gun

Regain portal gun

Potato portal gun

Flashlight

Portals work anywhere

Change portal size (w=width, h=height)

First person view

Third person view

Invincibility

Lists the physical properties of the object the cursor is over

For a more exhaustive list of the command codes check out this forum.

Puzzle Maker Controls

Figure1

Controls

  • Right-click once to select a panel. Double-click to select the entire wall the panel is located on. Holding SHIFT makes it possible to select multiple panels or items. 
  • Once a panel or wall is selected (highlights yellow), use the ‘+’ and ‘-’ keys to push the wall forwards or backwards, making the room larger or smaller.
  • On the left-hand side, there are 32 puzzle items that can be placed in the room. Each item has its own function within the game (the best way to learn their functions is to play a few levels). 
  • The key is to combine them in a sequential order, so that the level is possible to complete yet still challenges the player.
  • Along with the entrance and exit doors, these items can be dragged and placed virtually anywhere in the room.
  • Dragging an item while holding CTRL copies that item.
Figure6

Control options

  • One puzzle item of note is the Contraption cube. There are many cubes within the game, but the benefit of the Contraption cube is that its mass, friction, and elasticity can be manipulated. This provides physics teachers and students the option to create experiments where the effect of changing these variables can be observed.
  • For a detailed description of the controls and puzzle items check out this portal wiki.

topic discussion
comments powered by Disqus

Your feedback has been successfully sent! You will receive a response as soon as possible from a member of our Educade team.