1. Procedural Content Generation
David Maung, Josh Owusu-Dekyi, Ben Trivett, and Tim McLean

2. Outline Why PCG? Pros and Cons of Some PCG Methods
Dynamic Content Generation
Random Content Generation
User Mediated Content Generation
Some Criticisms of PCG
Games With PCG
Next Time
Questions?

3. Why PCG? Creates a lot of game content very quickly.
Provides replayability through more content.
Realistically model things like vegetation and erosion much more accurately and quickly than by hand.

4. General PCG Methods Dynamic Content Generation
Entire game world generated based on algorithm.
Only parts around the player are in memory.
Random Content Generation
Levels are randomly generated at runtime.
Used a lot in Rogue-likes.
User Mediated Content
Levels are generated randomly.
The levels are then evaluated and hand edited by developer/player.

5. Advantages of Dynamic Content Generation
Doesn't hog memory for things you can't even see.
World is persistent despite being regenerated on the fly.
Theoretically possible to have a truly infinite game.
Malevolence: The Sword of Ahkranox [2]

6. Disadvantages of Dynamic Content Generation
Constantly uses processor power to generate the map.
Usually only used if you want a very large game world.
Very difficult to make local changes.
Difficult to test that everything is sufficiently interesting.
Noctis[3]

7. Advantages of Random Content Generation
Infinite amount of different levels.
Most likely will not play the same level more than once.
Spelunky

8. Disadvantages of Random Content Generation
Difficult to guarantee that every possible generated level "works".
Hard to ensure that there are no boring levels.
Difficult to ensure difficulty is consistent between corresponding levels.
Spelunky again

9. Advantages of User Mediated Content
Majority of level design work is still done automatically.
Lets designers fix issues in the levels before release.
Gives levels a sense of purpose.
Can spark creativity in level designers.
AaaaaAAaaaAAAaaAAAAaAAAAA!!! [4]

10. Disadvantages of User Mediated Content
Content is not infinite, because it is pre-generated.
Still relying on some hand editing:
Takes more time to generate content.
Still need level designers.
SSX[5]

11. Criticisms of PCG Content can seem uninspired.
Setting up infrastructure takes time.
Law of Diminishing Marginal Utility.
Not a real thing.

12. PCG Game Examples Dwarf Fortress SSX Civilization (series) Minecraft
FTL: Faster Than Light
Diablo (series)
The Elder Scrolls Series

13. Dwarf Fortress
Part roguelike, part city building game released in 2006.
Uses mid-point displacement algorithm to create base elevation information.
Erodes the terrain with simulation of weather, volcanic activity, temperature models, and other effects.
Uses trade simulation to create roads and villages.

14. Dwarf Fortress Cont.

15. SSX
Continuation of the SSX snowboarding series and released by EA this past February.
Mountains and courses were to be initially created solely with PCG.
Courses felt mechanical, and not organic/smooth.
Used NASA topographic model as a base for mountain creation.
Used Houdini to procedurally place hazards and craft mountains into courses.

16. SSX Cont.

17. SSX Cont. Avalanches are procedurally generated.
Deadly Descent mode creates extra hazards for the player to avoid such as extra trees, rocks, avalanches, thin air, and darkness.

18. Civilization (series)
Maps are procedurally generated based upon constraints specified in scripting language.
Modding tools are made available so that players can create their own maps.

19. Minecraft
World was originally generated with 2D Perlin Noise heightmaps.
Problems with dull terrain.
Switched to 3D Perlin Noise with linear interpolation.
World is divided into biomes using Whittaker Diagrams.
"Infinite" map are not truely infinite as game becomes buggy at extreme distances,

20. Minecraft Cont.
No win scenarios

21. FTL: Faster Than Light
Space roguelike funded through Kickstarter and released this past September.
World is divided into sectors which is further divided into beacons.

22. FTL Cont.
More unwinnable situations
Small set of scenarios

23. Diablo (series)
The earlier entries had more procedurally generated towns and dungeons.
Diablo III has a hand-crafted hub, and uses larger tiles leading to less variety between runs.

24. Elder Scrolls (series)
The Elder Scrolls II Daggerfell
World is procedurally generated at installation.
Wilderness, dungeons, quests, and NPCs are as well.
Towns and cities are handcrafted for better navigation.
Landmass is twice the size of the British Isles.
Easy to get lost and difficult to navigate.

25. Elder Scrolls Cont. The Elder Scrolls V: Skyrim
Much more of the game is handcrafted including dungeons.
Randomly generated quests are used to pad out the handcrafted ones.
Quests are easier to complete as the locations are easier to find.
Map is much smaller than Daggerfall's.
~41 sq. km vs ~400,000 sq. km

26. Next Time Middleware used to help in creation of PCG.
Unity Tutorial for generating PCG.

27. References http://www.lostgarden.com/2007/02/content-is-bad.html

28. Questions?