Jump to content
  • Advertisement
Sign in to follow this  
spacekid434

Perlin noise and procedural generation

This topic is 2517 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

I've recently been working on a 2d RPG adventure game in Java. I have world loading among other things and I want to use procedural generation for the landscape of the game world.

I have had no previous experience with procedural generation so this was quite a learning curve for me and I feel I have done fairly well. I finally managed to make a Perlin noise demo with help from this article here and I'm fairly happy of the result (that demo uses a persistence of 1 and 8 octaves).

Here is the code for my Perlin noise. It's very fast to generate compared to some of the other algorithms I've tried. Im using a linear interpolate method because I don't notice the difference between a cos one except for the fact that linear is MUCH quicker...


double[][] genWhiteNoise(){
Random random = new Random(seed);
double[][] noise = new double[width][height];

for(int x = 0; x < width; x++){
for(int y = 0; y < height; y++){
noise[x][y] = random.nextDouble() % 1;
}
}

return noise;
}

double[][] generateSmoothNoise(double[][] baseNoise, int octave){
double[][] smoothNoise = new double[width][height];

int samplePeriod = 1 << octave;
double sampleFrequency = 1.0f / samplePeriod;

for(int x = 0; x < width; x++){
int sample_x0 = (x / samplePeriod) * samplePeriod;
int sample_x1 = (sample_x0 + samplePeriod) % width;
double horizontal_blend = (x - sample_x0) * sampleFrequency;

for(int y = 0; y < height; y++){
int sample_y0 = (y / samplePeriod) * samplePeriod;
int sample_y1 = (sample_y0 + samplePeriod) % height;
double vertical_blend = (y - sample_y0) * sampleFrequency;

double top = interpolate(baseNoise[sample_x0][sample_y0], baseNoise[sample_x1][sample_y0], horizontal_blend);

double bottom = interpolate(baseNoise[sample_x0][sample_y1], baseNoise[sample_x1][sample_y1], horizontal_blend);

smoothNoise[x][y] = interpolate(top, bottom, vertical_blend);
}
}

return smoothNoise;
}

double[][] perlinNoise(double[][] baseNoise, int octaveCount){
double[][][] smoothNoise = new double[octaveCount][][];

for(int i = 0; i < octaveCount; i++){
smoothNoise = generateSmoothNoise(baseNoise, i);
}

double[][] perlinNoise = new double[width][height];
double amplitude = 1.0;
double totalAmplitude = 0.0d;

for(int octave = octaveCount - 1; octave >= 0; octave--){
amplitude *= persistance;
totalAmplitude += amplitude;

for(int x = 0; x < width; x++){
for(int y = 0; y < height; y++){
perlinNoise[x][y] += smoothNoise[octave][x][y] * amplitude;
}
}
}

for(int x = 0; x < width; x++){
for(int y = 0; y < height; y++){
perlinNoise[x][y] /= totalAmplitude;
}
}

return perlinNoise;
}


First off, can someone please tell me if the noise I have generated if suitable for random world generation or if it's not, can they give me some tips and/or links to good examples.

and second, can someone please tell me a good place to start for turning that Perlin noise into a game world. I am using a tile based system and i plan on having mountains, sand dunes, forests and cities (they wont be randomly generated but they will have a random location in the world based on some placement parameters).

Any help would be very much appreciated.

Share this post


Link to post
Share on other sites
Advertisement
I'm not sure it uses perlin noise specifically, but is this similar to what you're after?

http://members.gamedev.net/vertexnormal/tutorial_randlev1.html

You could quantise the noise values into discrete bands, and assign each band a tileset - grass, rock, snow, lava. You could also need edge tiles, depending on the look you're going for.

Can you show an image of the noise you're generating?

Share this post


Link to post
Share on other sites
Thanks, I'll have a look at that website when I'm back home.

I did put a link to my perlin demo in the post but here's the image anyway:

Untitled.png

Thanks

Share this post


Link to post
Share on other sites
Procedural terrain generation is an interesting topic, I'm working on a 2D MMORTS and I used the Square-Diamond Algorithm for terrain creation, I am quite happy with the result. This is a screenshot of the terrain generated for my game.

2re639y.gif

This is a great tutorial to understand the algorithm wich is easy to implement once you understand how it works
http://gameprogrammer.com/fractal.html

Share this post


Link to post
Share on other sites
How you translate your noise functions to a game world depends on a great many factors. Does a cell or unit in the noise map translate to a single tile in the world, or does it translate to a sub-map or region? What sorts of characteristics can a tile or region have? Typically, you're going to use more than just a single layer of noise. As an example, in this journal post, I use several layers of noise and turbulence denoting the shape of an island, elevation and roughness of terrain, aridity, etc... and translate units into tiles in a simple tile map:

blogentry-47547-0-72940200-1296083423_thumb.jpg

Translated into tiles:

blogentry-47547-0-43024200-1296084301_thumb.jpg

This is a very simple example. You can get more complex depending on your needs. All sorts of information can be simulated using noise maps: elevation, placement of regions, density of vegetation, etc... Add a few simulated modeling processes (erosion, weather patterns) and you can come up with some pretty complex worlds.

Share this post


Link to post
Share on other sites
Oooh, me too me too me too Island Applet. it's essentially a 2d noise heightmap that gets modulated with another noise function to create regions of different "steepness".

Just get a noise function/generator some way to output images based on it and start playing. I starts getting intuitive pretty quick.

Share this post


Link to post
Share on other sites
I'd also suggest looking into Ken's followup version: "Simplex Noise" as it runs considerably faster, fixes a couple of visible pattern issues in the original and is much easier overall. From there, another source of information would be the book from the masters themselves: http://www.amazon.com/Texturing-Modeling-Third-Procedural-Approach/dp/1558608486/ref=sr_1_1?ie=UTF8&qid=1327285046&sr=8-1 It's an older book but given Perlin, Musgrave and Worley talk about how they use noise and variations, some of the helper functions listed in Worley's section I believe (bias/gain being two of my favorites) are excellent starting points for getting a better understanding of how to fiddle with the output of noise functions.

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

GameDev.net is your game development community. Create an account for your GameDev Portfolio and participate in the largest developer community in the games industry.

Sign me up!