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.

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?

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:



Thanks

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.



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

<personally removed due to accidental duplicate post, check history if curious>

i used perlin noise and ridged multi-fractal noise in mine to build biome, temp, wind, and rainfall maps. The library i used was Libnoise http://libnoise.sourceforge.net

Here is an early prototype:

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.