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Introduce a marble-like noise texture

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This commit is contained in:
Jean-Michel Gorius 2022-11-13 16:01:49 +01:00
parent 8400ea96aa
commit fc35055466
3 changed files with 18 additions and 3 deletions
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11
perlin.c
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@ -84,3 +84,14 @@ double perlin_noise(const PerlinData *data, Point3 p) {
return perlin_interp(c, u, v, w); return perlin_interp(c, u, v, w);
} }
double perlin_turbulence(const PerlinData *data, Point3 p, int depth) {
double accum = 0.0;
double weight = 1.0;
for (int i = 0; i < depth; ++i) {
accum += weight * perlin_noise(data, p);
weight *= 0.5;
p = (Point3){2 * p.x, 2 * p.y, 2 * p.z};
}
return fabs(accum);
}

3
perlin.h
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@ -5,10 +5,13 @@
#include "point3.h" #include "point3.h"
#define PERLIN_DEFAULT_POINT_COUNT 256 #define PERLIN_DEFAULT_POINT_COUNT 256
#define PERLIN_DEFAULT_TURBULENCE_DEPTH 7
typedef struct PerlinData PerlinData; typedef struct PerlinData PerlinData;
PerlinData *perlin_init(int point_count, Arena *arena); PerlinData *perlin_init(int point_count, Arena *arena);
double perlin_noise(const PerlinData *data, Point3 p); double perlin_noise(const PerlinData *data, Point3 p);
double perlin_turbulence(const PerlinData *data, Point3 p, int depth);
#endif /* INCLUDED_PERLIN_H */ #endif /* INCLUDED_PERLIN_H */

7
texture.c
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@ -65,8 +65,9 @@ Color checker_value(const CheckerTexture *checker, double u, double v,
Color perlin_value(const PerlinNoiseTexture *perlin, Point3 p) { Color perlin_value(const PerlinNoiseTexture *perlin, Point3 p) {
double noise_value = double noise_value =
0.5 * (1.0 + perlin_noise(perlin->data, (Point3){perlin->scale * p.x, 0.5 *
perlin->scale * p.y, (1.0 + sin(perlin->scale * p.z +
perlin->scale * p.z})); 10 * perlin_turbulence(perlin->data, p,
PERLIN_DEFAULT_TURBULENCE_DEPTH)));
return color_mul_const(noise_value, (Color){1.0, 1.0, 1.0}); return color_mul_const(noise_value, (Color){1.0, 1.0, 1.0});
} }