How does one get started with procedural generation?

Question

Procedural generation has been brought into the spotlight recently (by Spore, MMOs, etc), and it seems like an interesting/powerful programming technique.

My questio

Answer 1

(More than 10 years later ...)

Procedural generation only means that code is used to generate the data instead of it being hand made. For example if you want to generate a forest with various trees you are not going to design each tree by hand, thus coding is more efficient to generate the variations. It could be the generation of the tree graphics, size, structure, placement ...

In general there is some kind of interation with a few rules, in addition to that you can add some randomness and logic of your own, combine all of these techniques ... Anything somewhat chaotic but not too chaotic can yield interesting results.

Here are a few notable techniques:

• https://en.wikipedia.org/wiki/Cellular_automaton
• https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life (notable cellular automaton)
• Book: https://en.wikipedia.org/wiki/A_New_Kind_of_Science
• Fractals: https://en.wikipedia.org/wiki/Fractal
• Plants: https://en.wikipedia.org/wiki/L-system
• Terrain or maps, textures, smoke, clouds, turbulence: https://en.wikipedia.org/wiki/Perlin_noise
• Terrain or maps: https://en.wikipedia.org/wiki/Voronoi_diagram

A few games famous for their procedural generation:

• https://en.wikipedia.org/wiki/Rogue_(video_game) and roguelikes in general
• https://en.wikipedia.org/wiki/Elite_(video_game) random seed ...
• https://en.wikipedia.org/wiki/.kkrieger The entire game uses only 97,280 bytes of disk space.

Video tutorial about Procedural Landmass Generation.

Conference on procedural content generation for games, has a lot of videos on the topic: everythingprocedural

Have fun.

Answer 2

the most important thing is to analyze how roads, cities, blocks and buildings are structured. find out what all eg buildings have in common. look at photos, maps, plans and reality. if you do that you will be one step ahead of people who consider city building as a merely computer-technological matter.

next you should develop solutions on how to create that geometry in tiny, distinct steps. you have to define rules that make up a believable city. if you are into 3d modelling you have to rethink a lot of what you have learned so the computer can follow your instructions in any situation.

in order to not loose track you should set up a lot of operators that are only responsible for little parts of the whole process. that makes debugging, expanding and improving your system much easier. in the next step you should link those operators and check the results by changing parameters.

i have seen too many "city generators" that mainly consist of random-shaped boxes with some window textures on them : (

Answer 3

There is an excellent book about the topic:

http://www.amazon.com/Texturing-Modeling-Third-Procedural-Approach/dp/1558608486

It is biased toward non-real-time visual effects and animation generation, but the theory and ideas are usable outside of these fields, I suppose.

It may also worth to mention that there is a professional software package that implements a complete procedural workflow called SideFX's Houdini. You can use it to invent and prototype procedural solutions to problems, that you can later translate to code.

While it's a rather expensive package, it has a free evaluation licence, which can be used as a very nice educational and/or engineering tool.

Answer 4

If you want an example of a world generator simulation plates tectonics, erosion, rain-shadow, etc. take a look at: https://github.com/ftomassetti/lands

On top of that there is also a civilizations evolution simulator:

https://github.com/ftomassetti/civs

A blog full on interesting resource is:

dungeonleague.com/

It is abandoned now but you should read all its posts

Answer 5

I'm not an expert on this, but I can try and contribute a few answers:

1. NetHack and it's brethern are open source and rely heavily on procedural generation of levels (maps). Link to the downloads of it. If you are more interested in landscape/texture/cloud generation, I'd recommend you search Gamasutra and GameDev which have quite a few articles on those subjects.

2. AFAIK I don't think there is much difference between languages. Most of the code you see will be in C/CPP because it's still very much the official language of Game Developers, but you can use anything you want...

3. Well it depends if you have a project that can benefit from such technology. I saw procedural generation used in simulators for the army (which can be considered a game, although they are not very playable :)).

And a small note - my definition if procedural generation is anything generating a lot of data from a small amount of rules or patterns and lots of randomness, your results may vary :)

Answer 6

You should probably start with a little theory and simple examples such as the midpoint displacement algorithm. You should also learn a little about Perlin Noise if you are interested in generating graphics. I used this to get me started with my final year project on procedural generation.

Fractals are closely related to procedural generation.

Terragen and SpeedTree will show you some amazing possibilities of procedural generation.

Procedural generation is a technique that can be used in any language (it is definitely not restricted to procedural languages such as C, as it can be used in OO languages such as Java, and Logic languages such as Prolog). A good understanding of recursion in any language will strengthen your grasp of Procedural Generation.

As for 'serious' or non-game code, procedural generation techniques have been used to:

• simulate the growth of cities in order to plan for traffic management
• to simulate the growth of blood vessels
• SpeedTree is used in movies and architectural presentations