144 lines
5.8 KiB
C++
144 lines
5.8 KiB
C++
#include <mitsuba/render/noise.h>
|
|
|
|
MTS_NAMESPACE_BEGIN
|
|
|
|
#define GRAD_PERLIN 1
|
|
|
|
// Based on Ken Perlin's improved noise reference implementation
|
|
#define NOISE_PERM_SIZE 256
|
|
static int NoisePerm[2 * NOISE_PERM_SIZE] = {
|
|
151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, 140,
|
|
36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10, 23, 190, 6, 148, 247, 120,
|
|
234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 11, 32, 57, 177, 33,
|
|
88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175, 74, 165, 71,
|
|
134, 139, 48, 27, 166, 77, 146, 158, 231, 83, 111, 229, 122, 60, 211, 133,
|
|
230, 220, 105, 92, 41, 55, 46, 245, 40, 244, 102, 143, 54, 65, 25, 63,
|
|
161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18, 169, 200, 196, 135, 130,
|
|
116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250,
|
|
124, 123, 5, 202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47,
|
|
16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, 119, 248, 152, 2, 44, 154,
|
|
163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129, 22, 39, 253, 19, 98,
|
|
108, 110, 79, 113, 224, 232, 178, 185, 112, 104, 218, 246, 97, 228, 251, 34,
|
|
242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51, 145, 235, 249, 14,
|
|
239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204, 176, 115, 121,
|
|
50, 45, 127, 4, 150, 254, 138, 236, 205, 93, 222, 114, 67, 29, 24, 72, 243,
|
|
141, 128, 195, 78, 66, 215, 61, 156, 180, 151, 160, 137, 91, 90, 15, 131, 13,
|
|
201, 95, 96, 53, 194, 233, 7, 225, 140, 36, 103, 30, 69, 142, 8, 99, 37, 240,
|
|
21, 10, 23, 190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219,
|
|
203, 117, 35, 11, 32, 57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136,
|
|
171, 168, 68, 175, 74, 165, 71, 134, 139, 48, 27, 166, 77, 146, 158, 231, 83,
|
|
111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 55, 46, 245, 40, 244, 102,
|
|
143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18,
|
|
169, 200, 196, 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3,
|
|
64, 52, 217, 226, 250, 124, 123, 5, 202, 38, 147, 118, 126, 255, 82, 85, 212,
|
|
207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, 119,
|
|
248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129,
|
|
22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104, 218,
|
|
246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81,
|
|
51, 145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184,
|
|
84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205, 93, 222,
|
|
114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156, 180
|
|
};
|
|
|
|
inline static Float grad(int x, int y, int z, Float dx, Float dy, Float dz) {
|
|
int h = NoisePerm[NoisePerm[NoisePerm[x]+y]+z];
|
|
h &= 15;
|
|
#if defined(GRAD_PERLIN)
|
|
/* Based on Ken Perlin's improved Noise reference implementation */
|
|
Float u = h<8 ? dx : dy;
|
|
Float v = h<4 ? dy : h==12 || h==14 ? dx : dz;
|
|
#elif defined(GRAD_PBRT)
|
|
/* PBRT's implementation uses the hashes somewhat
|
|
differently. Possibly, this is just a typo */
|
|
Float u = h<8 || h==12 || h==13 ? dx : dy;
|
|
Float v = h<4 || h==12 || h==13 ? dy : dz;
|
|
#endif
|
|
return ((h&1) ? -u : u) + ((h&2) ? -v : v);
|
|
}
|
|
|
|
inline static Float noiseWeight(Float t) {
|
|
Float t3 = t*t*t, t4 = t3*t, t5 = t4*t;
|
|
return 6.0f*t5 - 15.0f*t4 + 10.0f*t3;
|
|
}
|
|
|
|
Float Noise::perlinNoise(const Point &p) {
|
|
// Compute noise cell coordinates and offsets
|
|
int ix = floorToInt(p.x),
|
|
iy = floorToInt(p.y),
|
|
iz = floorToInt(p.z);
|
|
|
|
Float dx = p.x - ix,
|
|
dy = p.y - iy,
|
|
dz = p.z - iz;
|
|
|
|
// Compute gradient weights
|
|
ix &= (NOISE_PERM_SIZE-1);
|
|
iy &= (NOISE_PERM_SIZE-1);
|
|
iz &= (NOISE_PERM_SIZE-1);
|
|
|
|
Float w000 = grad(ix, iy, iz, dx, dy, dz);
|
|
Float w100 = grad(ix+1, iy, iz, dx-1, dy, dz);
|
|
Float w010 = grad(ix, iy+1, iz, dx, dy-1, dz);
|
|
Float w110 = grad(ix+1, iy+1, iz, dx-1, dy-1, dz);
|
|
Float w001 = grad(ix, iy, iz+1, dx, dy, dz-1);
|
|
Float w101 = grad(ix+1, iy, iz+1, dx-1, dy, dz-1);
|
|
Float w011 = grad(ix, iy+1, iz+1, dx, dy-1, dz-1);
|
|
Float w111 = grad(ix+1, iy+1, iz+1, dx-1, dy-1, dz-1);
|
|
|
|
// Compute trilinear interpolation of weights
|
|
Float wx = noiseWeight(dx),
|
|
wy = noiseWeight(dy),
|
|
wz = noiseWeight(dz);
|
|
|
|
Float x00 = lerp(wx, w000, w100),
|
|
x10 = lerp(wx, w010, w110),
|
|
x01 = lerp(wx, w001, w101),
|
|
x11 = lerp(wx, w011, w111),
|
|
y0 = lerp(wy, x00, x10),
|
|
y1 = lerp(wy, x01, x11);
|
|
|
|
return lerp(wz, y0, y1);
|
|
}
|
|
|
|
Float Noise::fbm(const Point &p, const Vector &dpdx,
|
|
const Vector &dpdy, Float omega, int maxOctaves) {
|
|
// Compute number of octaves for antialiased FBm
|
|
Float s2 = std::max(dpdx.lengthSquared(), dpdy.lengthSquared());
|
|
Float foctaves = std::min((Float) maxOctaves, 1.f - .5f * log2(s2));
|
|
int octaves = (int) foctaves;
|
|
|
|
// Compute sum of octaves of noise for FBm
|
|
Float sum = 0., lambda = 1., o = 1.;
|
|
for (int i = 0; i < octaves; ++i) {
|
|
sum += o * perlinNoise(lambda * p);
|
|
lambda *= 1.99f;
|
|
o *= omega;
|
|
}
|
|
Float partialOctave = foctaves - octaves;
|
|
sum += o * smoothStep(.3f, .7f, partialOctave)
|
|
* perlinNoise(lambda * p);
|
|
return sum;
|
|
}
|
|
|
|
Float Noise::turbulence(const Point &p, const Vector &dpdx,
|
|
const Vector &dpdy, Float omega, int maxOctaves) {
|
|
// Compute number of octaves for antialiased FBm
|
|
Float s2 = std::max(dpdx.lengthSquared(), dpdy.lengthSquared());
|
|
Float foctaves = std::min((Float) maxOctaves, 1.f - .5f * log2(s2));
|
|
int octaves = (int) foctaves;
|
|
|
|
// Compute sum of octaves of noise for turbulence
|
|
Float sum = 0., lambda = 1., o = 1.;
|
|
for (int i = 0; i < octaves; ++i) {
|
|
sum += o * std::abs(perlinNoise(lambda * p));
|
|
lambda *= 1.99f;
|
|
o *= omega;
|
|
}
|
|
Float partialOctave = foctaves - octaves;
|
|
sum += o * smoothStep(.3f, .7f, partialOctave)
|
|
* std::abs(perlinNoise(lambda * p));
|
|
return sum;
|
|
}
|
|
|
|
MTS_NAMESPACE_END
|