# Perlin Noise?

Hello, and I am currently working on yet another minecraft clone (yes, I know :cranky:) and I was wondering, how could I implement Perlin Noise in my game? I already have the code for the Perlin Noise, but I don’t know how to generate it.

code:

``````public class Noise {
private static Random random = new Random(new Random().nextLong());

private static float[][] generateWhiteNoise(int width, int height) {
float[][] noise = new float[width][height];

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

return noise;
}

private static float[][] generateSmoothNoise(float[][] baseNoise, int octave) {
baseNoise = new float[octave][octave];
int width = baseNoise.length;
int height = baseNoise.length;

float[][] smoothNoise = new float[width][height];

int samplePeriod = 1 << octave; // calculates 2 ^ k
float sampleFrequency = 1.0f / samplePeriod;

for (int i = 0; i < width; i++) {
// calculate the horizontal sampling indices
int sample_i0 = (i / samplePeriod) * samplePeriod;
int sample_i1 = (sample_i0 + samplePeriod) % width; // wrap around
float horizontal_blend = (i - sample_i0) * sampleFrequency;

for (int j = 0; j < height; j++) {
// calculate the vertical sampling indices
int sample_j0 = (j / samplePeriod) * samplePeriod;
int sample_j1 = (sample_j0 + samplePeriod) % height; // wrap
// around
float vertical_blend = (j - sample_j0) * sampleFrequency;

// blend the top two corners
float top = interpolate(baseNoise[sample_i0][sample_j0],
baseNoise[sample_i1][sample_j0], horizontal_blend);

// blend the bottom two corners
float bottom = interpolate(baseNoise[sample_i0][sample_j1],
baseNoise[sample_i1][sample_j1], horizontal_blend);

// final blend
smoothNoise[i][j] = interpolate(top, bottom, vertical_blend);
}
}

return smoothNoise;
}

private static float interpolate(float x0, float x1, float alpha) {
return x0 * (1 - alpha) + alpha * x1;
}

private static float[][] generatePerlinNoise(float[][] baseNoise,
int octaveCount) {
int width = baseNoise.length;
int height = baseNoise[0].length;

float[][][] smoothNoise = new float[octaveCount][][]; // an array of 2D
// arrays
// containing

float persistance = 0.5f;

// generate smooth noise
for (int i = 0; i < octaveCount; i++) {
smoothNoise[i] = generateSmoothNoise(baseNoise, i);
}

float[][] perlinNoise = new float[width][height];
float amplitude = 0.0f; // the bigger, the more big mountains
float totalAmplitude = 0.0f;

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

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

for (int i = 0; i < width; i++) {
for (int j = 0; j < height; j++) {
perlinNoise[i][j] /= totalAmplitude;
perlinNoise[i][j] = (float) (Math.floor(perlinNoise[i][j] * 25));
}
}

return perlinNoise;
}

public static void generate(int width, int length) {
float[][] noise = generateSmoothNoise(generateWhiteNoise(width, length), 5);
}
}
``````
``````public class World {
public static final int CHUNK_SIZE = 16;
private Block[][][] blocks;

public void update() {

}

public World() {
blocks = new Block[CHUNK_SIZE][CHUNK_SIZE][CHUNK_SIZE];
for(int x=0; x<CHUNK_SIZE;x++) {
for(int y=0;y<CHUNK_SIZE;y++) {
for(int z=0;z<CHUNK_SIZE;z++) {
blocks[x][y][z] = new Block(BlockType.BlockType_Default);
blocks[x][y][z].render();
}
GL11.glTranslatef(0, 2, 0);
}
}
}

}
``````

http://accidentalnoise.sourceforge.net/minecraftworlds.html

If you are just going to copy something, copy something that will make it easy to use instead.

[quote]I already have the code for the Perlin Noise, but I don’t know how to generate it.
[/quote]
Are you asking how to make a Perlin noise function?
Are you asking how to figure out what values to pass into the Perlin noise function call?
Are you asking what to do with the values that are returned by the calls?

…and there’s a search box in your upper right hand frame of this forum. Your question has probably been answered.