terrain

Real-time terrain generation using marching cubes
git clone git://git.christianermann.dev/terrain
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sdf.c (1065B)

      1 #include "perlin.h"
      2 #include "sdf.h"
      3 
      4 #include <math.h>
      5 
      6 f32 perlinSDF(const Vec3 p)
      7 { 
      8     return perlin(p[0] * 0.01f, p[1] * 0.01f, p[2] * 0.01f)
      9     + 0.5f * perlin(p[0] * 0.05f, p[1] * 0.05f, p[2] * 0.05f)
     10     + 0.1f * perlin(p[0] * 0.1f, p[1] * 0.1f, p[2] * 0.1f);
     11 } 
     12 
     13 f32 caveSDF(const Vec3 p)
     14 { 
     15     f32 o1 = perlin(p[0] * 0.01f, p[1] * 0.01f, p[2] * 0.01f);
     16 
     17     return o1;
     18 } 
     19 
     20 f32 terrainSDF(const Vec3 p)
     21 { 
     22     f32 o1 = 50.0f * perlin(p[0] * 0.005f, 0.0f, p[2] * 0.005f);
     23     f32 o2 =  2.0f * perlin(p[0] * 0.050f, 0.0f, p[2] * 0.050f);
     24     f32 o3 =  1.0f * perlin(p[0] * 0.100f, 0.0f, p[2] * 0.100f);
     25 
     26     f32 surface = p[1] - o1 - o2 - o3;
     27     f32 cave = perlinSDF(p);
     28 
     29     f32 k  = 32.0f;
     30     f32 h = 0.5f - 0.5f * (cave - surface) / k;
     31     if (h < 0.0f)
     32     { 
     33         h = 0.0f;
     34     } 
     35     if (h > 1.0f)
     36     { 
     37         h = 1.0f;
     38     } 
     39     
     40     f32 a = cave * (1.0f - h) + surface * h;
     41     f32 b = k * h * (1.0f - h);
     42     
     43     return a + b;
     44 } 
     45     
     46 f32 sphereSDF(const Vec3 p)
     47 { 
     48     return sqrtf(p[0] * p[0] + p[1] * p[1] + p[2] * p[2]) - 25.0f;
     49 }