raymarching hell

experiments/cubes/main.frag

@@ -0,0 +1,122 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
+
+#define PI 3.14159265359
+
+float rhombSDF(vec2 st) {
+  vec2 st1 = (st)*2.;
+  vec2 st2 = (vec2(st.x,0.-st.y)*2.-1.)*2.;
+  float triangle1 = max(abs(st1.x)*.866025+st1.y*.5,-st1.y*.5);
+  float triangle2 = max(abs(st2.x)*.866025+st2.y*.5,-st2.y*.5);
+  return max(triangle1, triangle2);
+}
+
+float rectSDF(vec2 st, vec2 s) {
+  return max(abs(st.x/s.x),abs(st.y/s.y));
+}
+
+float random (vec2 st) {
+    return fract(sin(dot(st.xy,
+                         vec2(12.9898,78.233)))*
+        43758.5453123);
+}
+
+float stroke(in float x_coor, float s, float width){
+  float d = step(s,x_coor+width*.5)-step(s,x_coor-width*.5);
+  return clamp(d, 0.,1.);
+}
+
+float triSDF(vec2 st) {
+  st = st*2.;
+  return max(abs(st.x)*.866025+st.y*.5,-st.y*.5);
+}
+
+vec2 rotate(vec2 st, float a) {
+  return mat2(cos(a),-sin(a),sin(a),cos(a))*(st);
+}
+
+
+float sphereSDF(vec3 p, float r) {
+  return length(p) - r;
+}
+
+float sceneSDF(vec3 ray) {
+  return sphereSDF(ray, .0001);
+}
+
+float boxSDF(vec3 p, vec3 b)
+{
+  vec3 q = abs(p) - b;
+  return length(max(q,0.0)) + min(max(q.x,max(q.y,q.z)),0.0);
+}
+
+mat4 rotateY(float theta) {
+  float c = cos(theta);
+  float s = sin(theta);
+
+  return mat4(
+      vec4(c,0,s,0),
+      vec4(0,1,0,0),
+      vec4(-s,0,c,0),
+      vec4(0,0,0,1)
+      );
+
+}
+mat4 rotation3d(vec3 axis, float angle) {
+  axis = normalize(axis);
+  float s = sin(angle);
+  float c = cos(angle);
+  float oc = 1.0 - c;
+
+  return mat4(
+    oc * axis.x * axis.x + c,           oc * axis.x * axis.y - axis.z * s,  oc * axis.z * axis.x + axis.y * s,  0.0,
+    oc * axis.x * axis.y + axis.z * s,  oc * axis.y * axis.y + c,           oc * axis.y * axis.z - axis.x * s,  0.0,
+    oc * axis.z * axis.x - axis.y * s,  oc * axis.y * axis.z + axis.x * s,  oc * axis.z * axis.z + c,           0.0,
+    0.0,                                0.0,                                0.0,                                1.0
+  );
+}
+
+
+float rayMarch(vec3 ro, vec3 rd, float start, float end, vec4 rot) {
+
+  float MAX_MARCHING_STEPS = 250.;
+  float EPSILON = 0.1;
+  float depth = start;
+  for (float i = 0.; i < MAX_MARCHING_STEPS; i++) {
+    vec3 p = ro + depth * rd;
+    p = (rotation3d(rot.xyz, rot.w) * vec4(p, 1.0)).xyz;
+    float d = boxSDF(p , vec3(.5,.5,.5));
+    depth += d;
+    if (d < EPSILON || depth > end) break;
+  }
+  return depth;
+}
+
+
+
+void main() {
+  vec2 st = (gl_FragCoord.xy-.5*u_resolution) / u_resolution.y;
+  float temp = 0.;
+  vec3 ro = vec3(0, 0, 5); //ray origin
+  vec3 rd = normalize(vec3(st, -1)); //ray direction 
+  float d = rayMarch(ro+vec3(0,.2,.0), rd, 0.,100.,vec4(.4,.8,-.9,.4));
+  d = min(d,rayMarch(ro+vec3(-.2,.0,.0), rd, 0.,100.,vec4(.2,.1,.3,.9)));
+  d = min(d,rayMarch(ro+vec3(-.2,-.8,.0), rd, 0.,100.,vec4(.2,.1,.3,.9)));
+  d = min(d,rayMarch(ro+vec3(-.2,.3,.0), rd, 0.,100.,vec4(.2,.1,.3,.9)));
+  d = min(d,rayMarch(ro+vec3(-.2,.0,-.8), rd, 0.,100.,vec4(.2,.1,.3,.9)));
+  d = 1.-d/7.;
+  vec3 col = vec3(d);
+  if (d > 100.0) {
+    //col = vec3(0.1);
+  } else {
+    //col = vec3(0.,0.,1.);
+  }
+    
+
+  gl_FragColor = vec4(col, 1.0);
+}