我是Perlin噪音的新手,我遇到了障碍。我从C ++翻译的perlin噪声函数似乎在一个八度音程中正常工作,但是我发现噪声的低八度音不会添加到原始的Perlin噪声中。这是我的代码:
public class Perlin {
float[][] generateWhiteNoise(int width, int height) {
Random random = new Random(0);
float[][] noise = new float[width][height];
for (int i = 0; i < noise.length; i++) {
for (int j = 0; j < noise[i].length; j++){
noise[i][j] = (float)random.nextDouble();
}
}
return noise;
}
float[][] generateSmoothNoise(float[][] baseNoise, int octave){
int width = baseNoise.length;
int height = baseNoise[0].length;
float[][] smoothNoise = baseNoise;
int samplePeriod = (int) Math.pow(2,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;
}
float interpolate(float x0, float x1, float alpha){
return (float) ((float)(x0) * (float)(1 - alpha) + (float)(alpha * x1));
}
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 = .5f;
//generate smooth noise
for (int i = 0; i<octaveCount; i++) {
System.out.println("Generating Smooth Noise: " + i);
smoothNoise[i] = generateSmoothNoise(baseNoise, i);
}
float[][] perlinNoise = new float[width][height];
float amplitude = 1.0f;
float totalAmplitude = 0.0f;
//blend noise together
for (int octave = octaveCount - 1; octave >= 0; octave--) {
amplitude *= persistance;
totalAmplitude += amplitude;
System.out.println("Adding smooth noise for octave: " + octave + " at amplitude: " + amplitude);
for (int i = 0; i < width; i++) {
for (int j = 0; j < height; j++) {
perlinNoise[i][j] += smoothNoise[octave][i][j] * amplitude;
}
}
}
//normalization
for (int i = 0; i < width; i++) {
for (int j = 0; j < height; j++) {
perlinNoise[i][j] /= totalAmplitude;
}
}
return perlinNoise;
}
public float[][] printVals(float[][] baseNoise){
baseNoise = generatePerlinNoise(generateWhiteNoise(800,800),6);
for(int i = 0; i<baseNoise.length; i++){
String row = "";
for(int j = 0; j<baseNoise[i].length;j++){
row+= (int)(baseNoise[i][j]*255) + " ";
}
System.out.println(row);
}
return baseNoise;
}
}
以下是我用来获取值的代码:
baseNoise = generatePerlinNoise(generateWhiteNoise(800,800),6);
以下是八度音程1,2,3和4的输出
任何帮助将不胜感激!
修改
通过反复试验,我发现最有可能出现问题的区域是generatePerlinNoise()
函数。如果我改变八度音阶,我会得到所需的噪音水平,这就是我想要的。这也意味着generateWhiteNoise()
和generateSmoothNoise()
有效。因此,在generatePerlinNoise()
混合中的某个地方存在问题,但它似乎应该有效。
答案 0 :(得分:0)
我找到了答案。我曾经以为generateSmoothNoise()
命令会给我多倍的八度perlin噪音。然而,我意识到我需要构建另一个命令,类似于混合平滑噪声以混合我的不同八度perlin噪声所发生的命令。
public float[][] generateMultiOctavePerlinNoise(int octaves, double persistence, double dropoff, int width, int height){
float[][][]noise = new float[octaves][width][height];
for(int i = octaves - 1; i > 0;i--){
noise[i] = generatePerlinNoise(generateWhiteNoise(width,height),octaves - i);
}
float[][] multiOctave = new float[width][height];
for(int a= 0; a<noise.length; a++){
persistence*= dropoff;
for(int i = 0; i<multiOctave.length; i++){
for(int j = 0; j<multiOctave[i].length; j++){
multiOctave[i][j] += noise[a][i][j]*persistence;
}
}
}
return multiOctave;
}