9_5_displacement

Code 9.5, Figure 9.9:

9_5_displacement.frag

#version 300 es precision mediump float; precision highp int; out vec4 fragColor; uniform float u_time; uniform vec2 u_resolution; //begin rot vec2 rot2(vec2 p, float t){ return vec2(cos(t) * p.x -sin(t) * p.y, sin(t) * p.x + cos(t) * p.y); } vec3 rotX(vec3 p, float t){ return vec3(p.x, rot2(p.yz, t)); } vec3 rotY(vec3 p, float t){ return vec3(p.y, rot2(p.zx, t)).zxy; } vec3 rotZ(vec3 p, float t){ return vec3(rot2(p.xy, t), p.z); } vec3 euler(vec3 p, vec3 t){ return rotZ(rotY(rotX(p, t.x), t.y), t.z); } //end rot //start hash uvec3 k = uvec3(0x456789abu, 0x6789ab45u, 0x89ab4567u); uvec3 u = uvec3(1, 2, 3); const uint UINT_MAX = 0xffffffffu; uint uhash11(uint n){ n ^= (n << u.x); n ^= (n >> u.x); n *= k.x; n ^= (n << u.x); return n * k.x; } uvec2 uhash22(uvec2 n){ n ^= (n.yx << u.xy); n ^= (n.yx >> u.xy); n *= k.xy; n ^= (n.yx << u.xy); return n * k.xy; } uvec3 uhash33(uvec3 n){ n ^= (n.yzx << u); n ^= (n.yzx >> u); n *= k; n ^= (n.yzx << u); return n * k; } float hash11(float p){ uint n = floatBitsToUint(p); return float(uhash11(n)) / float(UINT_MAX); } float hash21(vec2 p){ uvec2 n = floatBitsToUint(p); return float(uhash22(n).x) / float(UINT_MAX); } float hash31(vec3 p){ uvec3 n = floatBitsToUint(p); return float(uhash33(n).x) / float(UINT_MAX); } vec2 hash22(vec2 p){ uvec2 n = floatBitsToUint(p); return vec2(uhash22(n)) / vec2(UINT_MAX); } vec3 hash33(vec3 p){ uvec3 n = floatBitsToUint(p); return vec3(uhash33(n)) / vec3(UINT_MAX); } //end hash //start pnoise float gtable2(vec2 lattice, vec2 p){ uvec2 n = floatBitsToUint(lattice); uint ind = uhash22(n).x >> 29; float u = 0.92387953 * (ind < 4u ? p.x : p.y); //0.92387953 = cos(pi/8) float v = 0.38268343 * (ind < 4u ? p.y : p.x); //0.38268343 = sin(pi/8) return ((ind & 1u) == 0u ? u : -u) + ((ind & 2u) == 0u? v : -v); } float pnoise21(vec2 p){ vec2 n = floor(p); vec2 f = fract(p); float[4] v; for (int j = 0; j < 2; j ++){ for (int i = 0; i < 2; i++){ v[i+2*j] = gtable2(n + vec2(i, j), f - vec2(i, j)); } } f = f * f * f * (10.0 - 15.0 * f + 6.0 * f * f); return 0.5 * mix(mix(v[0], v[1], f[0]), mix(v[2], v[3], f[0]), f[1]) + 0.5; } float gtable3(vec3 lattice, vec3 p){ uvec3 n = floatBitsToUint(lattice); uint ind = uhash33(n).x >> 28; float u = ind < 8u ? p.x : p.y; float v = ind < 4u ? p.y : ind == 12u || ind == 14u ? p.x : p.z; return ((ind & 1u) == 0u? u: -u) + ((ind & 2u) == 0u? v : -v); } float pnoise31(vec3 p){ vec3 n = floor(p); vec3 f = fract(p); float[8] v; for (int k = 0; k < 2; k++ ){ for (int j = 0; j < 2; j++ ){ for (int i = 0; i < 2; i++){ v[i+2*j+4*k] = gtable3(n + vec3(i, j, k), f - vec3(i, j, k)) * 0.70710678; } } } f = f * f * f * (10.0 - 15.0 * f + 6.0 * f * f); float[2] w; for (int i = 0; i < 2; i++){ w[i] = mix(mix(v[4*i], v[4*i+1], f[0]), mix(v[4*i+2], v[4*i+3], f[0]), f[1]); } return 0.5 * mix(w[0], w[1], f[2]) + 0.5; } //end pnoise float sphereSDF(vec3 p){ return length(p) - 1.0; } float sceneSDF(vec3 p){ return sphereSDF(p)+ 0.1 * pnoise31(10.0 * p); } vec3 gradSDF(vec3 p){ float eps = 0.001; return normalize(vec3( sceneSDF(p + vec3(eps, 0.0, 0.0)) - sceneSDF(p - vec3(eps, 0.0, 0.0)), sceneSDF(p + vec3(0.0, eps, 0.0)) - sceneSDF(p - vec3(0.0, eps, 0.0)), sceneSDF(p + vec3(0.0, 0.0, eps)) - sceneSDF(p - vec3(0.0, 0.0, eps)) )); } void main(){ vec2 p = (gl_FragCoord.xy * 2.0 - u_resolution) / min(u_resolution.x, u_resolution.y); float t = u_time * 0.3; vec3 cPos = rotY(vec3(0.0, 0.0, 2.0), t); vec3 cDir = rotY(vec3(0.0, 0.0, - 1.0), t); vec3 cUp = rotY(vec3(0.0, 1.0, 0.0), t); vec3 cSide = cross(cDir, cUp); float targetDepth = 1.0; vec3 lDir = rotY(vec3(1.0), t); vec3 ray = cSide * p.x + cUp * p.y + cDir * targetDepth; vec3 rPos = ray + cPos; ray = normalize(ray); bool hit = false; for(int i = 0; i < 50; i ++ ){ if (sceneSDF(rPos) > 0.001){ rPos += sceneSDF(rPos) * ray; } else { float amb = 0.1; float diff = 0.9 * max(dot(normalize(lDir), gradSDF(rPos)), 0.0); vec3 col = vec3(1.0); fragColor.rgb = col * (diff + amb); break; } } fragColor.a = 1.0; }

#version 300 es
precision mediump float;
precision highp int;
out vec4 fragColor;
uniform float u_time;
uniform vec2 u_resolution;

//begin rot
vec2 rot2(vec2 p, float t){
  return vec2(cos(t) * p.x -sin(t) * p.y, sin(t) * p.x + cos(t) * p.y);
}

vec3 rotX(vec3 p, float t){
  return vec3(p.x, rot2(p.yz, t));
}

vec3 rotY(vec3 p, float t){
  return vec3(p.y, rot2(p.zx, t)).zxy;
}

vec3 rotZ(vec3 p, float t){
  return vec3(rot2(p.xy, t), p.z);
}

vec3 euler(vec3 p, vec3 t){
  return rotZ(rotY(rotX(p, t.x), t.y), t.z);
}
//end rot

//start hash
uvec3 k = uvec3(0x456789abu, 0x6789ab45u, 0x89ab4567u);
uvec3 u = uvec3(1, 2, 3);
const uint UINT_MAX = 0xffffffffu;

uint uhash11(uint n){
  n ^= (n << u.x);
  n ^= (n >> u.x);
  n *= k.x;
  n ^= (n << u.x);
  return n * k.x;
}

uvec2 uhash22(uvec2 n){
  n ^= (n.yx << u.xy);
  n ^= (n.yx >> u.xy);
  n *= k.xy;
  n ^= (n.yx << u.xy);
  return n * k.xy;
}

uvec3 uhash33(uvec3 n){
  n ^= (n.yzx << u);
  n ^= (n.yzx >> u);
  n *= k;
  n ^= (n.yzx << u);
  return n * k;
}

float hash11(float p){
  uint n = floatBitsToUint(p);
  return float(uhash11(n)) / float(UINT_MAX);
}

float hash21(vec2 p){
  uvec2 n = floatBitsToUint(p);
  return float(uhash22(n).x) / float(UINT_MAX);
}

float hash31(vec3 p){
  uvec3 n = floatBitsToUint(p);
  return float(uhash33(n).x) / float(UINT_MAX);
}

vec2 hash22(vec2 p){
  uvec2 n = floatBitsToUint(p);
  return vec2(uhash22(n)) / vec2(UINT_MAX);
}

vec3 hash33(vec3 p){
  uvec3 n = floatBitsToUint(p);
  return vec3(uhash33(n)) / vec3(UINT_MAX);
}
//end hash

//start pnoise
float gtable2(vec2 lattice, vec2 p){
  uvec2 n = floatBitsToUint(lattice);
  uint ind = uhash22(n).x >> 29;
  float u = 0.92387953 * (ind < 4u ? p.x : p.y);  //0.92387953 = cos(pi/8)
  float v = 0.38268343 * (ind < 4u ? p.y : p.x);  //0.38268343 = sin(pi/8)
  return ((ind & 1u) == 0u ? u : -u) + ((ind & 2u) == 0u? v : -v);
}

float pnoise21(vec2 p){
  vec2 n = floor(p);
  vec2 f = fract(p);
  float[4] v;
  for (int j = 0; j < 2; j ++){
    for (int i = 0; i < 2; i++){
      v[i+2*j] = gtable2(n + vec2(i, j), f - vec2(i, j));
    }
  }
  f = f * f * f * (10.0 - 15.0 * f + 6.0 * f * f);
  return 0.5 * mix(mix(v[0], v[1], f[0]), mix(v[2], v[3], f[0]), f[1]) + 0.5;
}

float gtable3(vec3 lattice, vec3 p){
  uvec3 n = floatBitsToUint(lattice);
  uint ind = uhash33(n).x >> 28;
  float u = ind < 8u ? p.x : p.y;
  float v = ind < 4u ? p.y : ind == 12u || ind == 14u ? p.x : p.z;
  return ((ind & 1u) == 0u? u: -u) + ((ind & 2u) == 0u? v : -v);
}

float pnoise31(vec3 p){
  vec3 n = floor(p);
  vec3 f = fract(p);
  float[8] v;
  for (int k = 0; k < 2; k++ ){
    for (int j = 0; j < 2; j++ ){
      for (int i = 0; i < 2; i++){
        v[i+2*j+4*k] = gtable3(n + vec3(i, j, k), f - vec3(i, j, k)) * 0.70710678;
      }
    }
  }
  f = f * f * f * (10.0 - 15.0 * f + 6.0 * f * f);
  float[2] w;
  for (int i = 0; i < 2; i++){
    w[i] = mix(mix(v[4*i], v[4*i+1], f[0]), mix(v[4*i+2], v[4*i+3], f[0]), f[1]);
  }
  return 0.5 * mix(w[0], w[1], f[2]) + 0.5;
}
//end pnoise

float sphereSDF(vec3 p){
  return length(p) - 1.0;
}

float sceneSDF(vec3 p){
  return sphereSDF(p)+ 0.1 * pnoise31(10.0 * p);
}

vec3 gradSDF(vec3 p){
  float eps = 0.001;
  return normalize(vec3(
    sceneSDF(p + vec3(eps, 0.0, 0.0)) - sceneSDF(p - vec3(eps, 0.0, 0.0)),
    sceneSDF(p + vec3(0.0, eps, 0.0)) - sceneSDF(p - vec3(0.0, eps, 0.0)),
    sceneSDF(p + vec3(0.0, 0.0, eps)) - sceneSDF(p - vec3(0.0, 0.0, eps))
  ));
}

void main(){
  vec2 p = (gl_FragCoord.xy * 2.0 - u_resolution) / min(u_resolution.x, u_resolution.y);
  
  float t = u_time * 0.3;
  vec3 cPos = rotY(vec3(0.0, 0.0, 2.0), t);
  vec3 cDir = rotY(vec3(0.0, 0.0, - 1.0), t);
  vec3 cUp = rotY(vec3(0.0, 1.0, 0.0), t);
  vec3 cSide = cross(cDir, cUp);
  float targetDepth = 1.0;
  
  vec3 lDir = rotY(vec3(1.0), t);
  
  vec3 ray = cSide * p.x + cUp * p.y + cDir * targetDepth;
  vec3 rPos = ray + cPos;
  ray = normalize(ray);
  bool hit = false;
  for(int i = 0; i < 50; i ++ ){
    if (sceneSDF(rPos) > 0.001){
      rPos += sceneSDF(rPos) * ray;
    } else {
      float amb = 0.1;
      float diff = 0.9 * max(dot(normalize(lDir), gradSDF(rPos)), 0.0);
      vec3 col = vec3(1.0);
      fragColor.rgb = col * (diff + amb);
      break;
    }
  }
  fragColor.a = 1.0;
}