9_10_norm
コード 9.11, 図 9.16:
9_10_norm.frag
#version 300 esprecision highp float;precision highp int;out vec4 fragColor;uniform float u_time;uniform vec2 u_resolution;//begin rotvec2 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 rotfloat kyoto(vec3 p){float scale = 1.0;return scale * (abs(p.x) + abs(p.y) + abs(p.z));}float shogi(vec3 p){float scale =1.;return scale * max(max(abs(p.x), abs(p.y)), abs(p.z));}float euc(vec3 p){float scale = 1.0;return scale * length(p);}float length_(vec3 p){float time = u_time * 0.2;float v0, v1;if (int(time) % 3 == 0){v0 = euc(p);v1 = shogi(p);} else if (int(time) % 3 == 1){v0 = shogi(p);v1 = kyoto(p);} else {v0 = kyoto(p);v1 = euc(p);}return mix(v0, v1, smoothstep(0.25, 0.75, fract(time)));}float length2(vec3 p){p = abs(p);float d = 4.0 * sin(0.5 * u_time) + 5.0;return pow(pow(p.x, d) + pow(p.y, d) + pow(p.z, d), 1.0 / d);}float sphereSDF(vec3 p){return length2(p) - 0.5;}float sceneSDF(vec3 p){return sphereSDF(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);vec3 t = vec3(u_time * 0.3);vec3 cPos = euler(vec3(0.0, 0.0, 2.0), t);vec3 cDir = euler(vec3(0.0, 0.0, - 1.0), t);vec3 cUp = euler(vec3(0.0, 1.0, 0.0), t);vec3 cSide = cross(cDir, cUp);float targetDepth = 1.0;vec3 lDir = euler(vec3(0.0, 0.0, 1.0), t);vec3 ray = cSide * p.x + cUp * p.y + cDir * targetDepth;vec3 rPos = ray + cPos;ray = ray / length2(ray);fragColor.rgb = vec3(0.0);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(0.0, 1.0, 1.0);fragColor.rgb = col * (diff + amb);break;}}fragColor.a = 1.0;}