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Fractional Brownian Motion

This commit is contained in:
Rémi Oudin 2018-02-13 23:38:24 +01:00
parent 6823552ee7
commit 2afd89dbf3
2 changed files with 18 additions and 1 deletions
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17
PerlinNoise.cpp
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@ -44,7 +44,7 @@ PerlinNoise::PerlinNoise(unsigned int seed) : ImplicitSurface(Point(0,0,0)) {
}
double PerlinNoise::operator() (double x, double y, double z) const {
return z - noise(x, 0, y);
return z - fBm(x, 0, y, 2, 0.3, 2.0);
}
double PerlinNoise::noise(double _x, double _y, double _z) const {
@ -111,6 +111,21 @@ double PerlinNoise::grad(int hash, double x, double y, double z) const {
return ((h & 1) == 0 ? u : -u) + ((h & 2) == 0 ? v : -v);
}
double PerlinNoise::fBm(double x, double y, double z, int octaves, double
lacunarity, double gain) const {
double amplitude = 1.0;
double frequency = 1.0;
double sum = 0.0;
for(int i = 0; i < octaves; ++i)
{
// sum += amplitude * (1-abs(noise(x * frequency, y * frequency, z * frequency)));
sum += amplitude * noise(x * frequency, y * frequency, z * frequency);
amplitude *= gain;
frequency *= lacunarity;
}
return sum;
}
Point PerlinNoise::normal_vector(double x, double y) {
double n_x_y = noise(x, y, 0);
double n_dx_y = noise(x + 0.01, y, 0);

2
PerlinNoise.hpp
View File

@ -16,6 +16,8 @@ class PerlinNoise : public ImplicitSurface {
double operator() (double _x, double _y, double _z) const;
double noise(double x, double y) const;
Point normal_vector(double x, double y);
double fBm(double x, double y, double z, int octaves, double
lacunarity, double gain) const;
virtual Point location_hint() const;
Point location_hint(double x, double z) const;