precision highp float; uniform float time; uniform vec2 mouse; uniform vec2 resolution; #define PI 3.14159265359 #define INV_PI 0.31830988618 #define TWO_PI 6.28318530718 #define saturate(x) clamp(x, 0.0, 1.0) vec2 random2(float x) { return fract(sin(x * vec2(12.9898, 51.431)) * vec2(43758.5453, 71932.1354)); } mat2 rotate(float r) { float c = cos(r); float s = sin(r); return mat2(c, s, -s, c); } float sdSphere(vec3 p, float r) { return length(p) - r; } float sdBox(vec3 p, vec3 b) { p = abs(p) - b; return length(max(p, 0.0)) + min(0.0, max(p.x, max(p.y, p.z))); } float sdTorus(vec3 p, vec2 t) { vec2 q = vec2(length(p.xz) - t.x, p.y); return length(q) - t.y; } float plane(vec3 ro, vec3 rd, float y) { float t = (y - ro.y) / rd.y; return t; } float map(vec3 p) { p.xy *= rotate(time * 0.5); p.xz *= rotate(time * 0.8); float db = sdBox(p, vec3(3.0)); float dt = sdTorus(p, vec2(4.0, 1.0)); float ds = sdSphere(p, 2.0) + sin(10.0 * p.x) * sin(10.0 * p.y) * sin(10.0 * p.z); float t = time * 0.8; float idx = mod(t, 2.0); float f = fract(t); float l = smoothstep(0.7, 1.0, f); if (idx < 1.0) { float v = l < 0.5 ? mix(db, ds, smoothstep(0.0, 1.0, l * 2.0)) : mix(ds, dt, smoothstep(0.0, 1.0, (l - 0.5) * 2.0)); return mix(db, v, l); } else { float v = l < 0.5 ? mix(dt, ds, smoothstep(0.0, 1.0, l * 2.0)) : mix(ds, db, smoothstep(0.0, 1.0, (l - 0.5) * 2.0)); return mix(dt, v, l); } } vec3 calcNormal(vec3 p) { float d = 0.01; return normalize(vec3( map(p + vec3(d, 0.0, 0.0)) - map(p - vec3(d, 0.0, 0.0)), map(p + vec3(0.0, d, 0.0)) - map(p - vec3(0.0, d, 0.0)), map(p + vec3(0.0, 0.0, d)) - map(p - vec3(0.0, 0.0, d)) )); } bool raymarch(vec3 ro, vec3 rd, float tmin, out float t) { vec3 p = ro; t = tmin; for (int i = 0; i < 32; i++) { float d = map(p); t += d; p += d * rd; if (d < 0.01) { return true; } } return false; } bool raymarchShort(vec3 ro, vec3 rd, float tmin, float near, out float t) { vec3 p = ro; t = tmin; for (int i = 0; i < 8; i++) { float d = map(p); t += d; p += d * rd; if (d < near) { return true; } } return false; } const vec3 LIGHT_COLOR = vec3(1.0) * 3.0; const vec3 OBJECT_COLOR = vec3(0.9, 0.2, 0.45); const vec3 FLOOR_COLOR = vec3(0.35, 0.4, 0.45); const vec3 AMBINET_LGIHT_COLOR = vec3(0.05); const float FLOOR_Y = -5.0; const vec3 LIGHT_POS = vec3(60.0, 15.0, -30.0); mat3 orthonormal(vec3 orthoY) { vec3 a = orthoY.x < 0.9 ? vec3(1.0, 0.0, 0.0) : vec3(0.0, 1.0, 0.0); vec3 orthoX = normalize(cross(orthoY, a)); vec3 orthoZ = cross(orthoX, orthoY); return mat3(orthoX, orthoY, orthoZ); } vec3 createSampleDir(mat3 ortho, float theta, float phi) { vec3 v = vec3(sin(theta) * cos(phi), cos(theta), sin(theta) * sin(phi)); return ortho * v; } vec3 orthonormal(vec3 normal, float theta, float phi) { vec3 orthoY = normal; vec3 a = normal.x < 0.9 ? vec3(1.0, 0.0, 0.0) : vec3(0.0, 1.0, 0.0); vec3 orthoX = normalize(cross(orthoY, a)); vec3 orthoZ = cross(orthoX, orthoY); vec3 n; n.x = sin(theta) * cos(phi); n.y = cos(theta); n.z = sin(theta) * sin(phi); return normalize(vec3(dot(vec3(orthoX.x, orthoY.x, orthoZ.x), n), dot(vec3(orthoX.y, orthoY.y, orthoZ.y), n), dot(vec3(orthoX.z, orthoY.z, orthoZ.z), n))); } vec3 skyColor() { return vec3(0.0); } float fresnelSchlick(float f0, float f90, float cosine) { return f0 + (f90 - f0) * pow(1.0 - cosine, 5.0); } vec3 diffuseNormalizedDisneyBrdf(vec3 reflectance, float dotNV, float dotNL, float dotLH, float roughness) { float bias = mix(0.0, 0.5, roughness); float factor = mix(1.0, 1.0 / 1.51, roughness); float fd90 = bias + 2.0 * dotLH * dotLH * roughness; float fl = fresnelSchlick(1.0, fd90, dotNL); float fv = fresnelSchlick(1.0, fd90, dotNV); return reflectance * INV_PI * fl * fv * factor; } float normalDistributionGgx(vec3 normal, vec3 halfDir, float roughness) { float roughness2 = roughness * roughness; float dotNH = saturate(dot(normal, halfDir)); float a = (1.0 + (roughness2 - 1.0) * dotNH * dotNH); return roughness2 * INV_PI / (a * a); } float maskingShadowingSmithJoint(vec3 normal, vec3 viewDir, vec3 lightDir, float roughness) { float roughness2 = roughness * roughness; float dotNV = saturate(dot(normal, viewDir)); float dotNL = saturate(dot(normal, lightDir)); float lv = 0.5 * (-1.0 + sqrt(1.0 + roughness2 * (1.0 / (dotNV * dotNV) - 1.0))); float ll = 0.5 * (-1.0 + sqrt(1.0 + roughness2 * (1.0 / (dotNL * dotNL) - 1.0))); return 1.0 / (1.0 + lv + ll); } vec3 fresnelSchlick(vec3 f0, float cosine) { return f0 + (1.0 - f0) * pow(1.0 - cosine, 5.0); } vec3 specularCookTorranceBrdf(vec3 reflectance, vec3 normal, vec3 viewDir, vec3 lightDir, float roughness) { vec3 halfDir = normalize(viewDir + lightDir); float dotNV = saturate(dot(normal, viewDir)); float dotNL = saturate(dot(normal, lightDir)); float dotVH = saturate(dot(viewDir, halfDir)); float d = normalDistributionGgx(normal, halfDir, roughness); float g = maskingShadowingSmithJoint(normal, viewDir, lightDir, roughness); vec3 f = fresnelSchlick(reflectance, dotVH); return d * g * f / (4.0 * dotNV * dotNL + 1e-5); } vec3 getObjectColor(vec3 normal, vec3 viewDir, vec3 lightDir) { vec3 halfDir = normalize(viewDir + lightDir); float dotNV = saturate(dot(normal, viewDir)); float dotNL = saturate(dot(normal, lightDir)); float dotLH = saturate(dot(lightDir, halfDir)); vec3 brdf = diffuseNormalizedDisneyBrdf(OBJECT_COLOR, dotNV, dotNL, dotLH, 0.5); return brdf * LIGHT_COLOR * dotNL + AMBINET_LGIHT_COLOR * OBJECT_COLOR; } const float FLOOR_ROUGHNESS = 0.2; float softShadow(vec3 ro, vec3 rd, float tmin, float k) { float res = 1.0; vec3 p = ro + tmin * rd; float t = tmin; for (int i = 0; i < 32; i++) { float d = map(p); p += d * rd; t += d; if (d < 0.02) { return 0.0; } res = min(res, k * d / t); } return res; } vec3 getFloorColor(vec3 normal, vec3 viewDir, vec3 lightDir, vec3 lightColor) { float dotNL = saturate(dot(normal, lightDir)); vec3 brdf = specularCookTorranceBrdf(FLOOR_COLOR, normal, viewDir, lightDir, FLOOR_ROUGHNESS); return brdf * lightColor * dotNL; } vec3 getLightDir(vec3 pos) { return normalize(LIGHT_POS - pos); } vec3 getColor(vec3 ro, vec3 rd) { float t; if (raymarch(ro, rd, 0.0, t)) { vec3 pos = ro + t * rd; vec3 normal = calcNormal(pos); return getObjectColor(normal, -rd, getLightDir(pos)); } else { float t = plane(ro, rd, FLOOR_Y); if (t < 0.0) { return skyColor(); } vec3 floorPos = ro + t * rd; vec3 floorNormal = vec3(0.0, 1.0, 0.0); vec3 refDir = reflect(rd, floorNormal); float shadow = softShadow(floorPos, getLightDir(floorPos), 0.01, 16.0); vec3 lightDir = getLightDir(floorPos); vec3 lightSpec = (0.5 + 0.5 * shadow) * getFloorColor(floorNormal, -rd, lightDir, LIGHT_COLOR); vec3 sum = vec3(0.0); mat3 ortho = orthonormal(refDir); for (int i = 0; i < 16; i++) { vec2 r = random2(float(i) + floorPos.x + floorPos.z); vec3 sampleDir = createSampleDir(ortho, FLOOR_ROUGHNESS * r.x * PI / 8.0, r.y * TWO_PI); if (dot(sampleDir, floorNormal) <= 0.0) { continue; } if (raymarchShort(floorPos, sampleDir, 0.01, 0.05, t)) { vec3 objPos = floorPos + t * sampleDir; vec3 objNormal = calcNormal(objPos); vec3 objColor = getObjectColor(objNormal, -sampleDir, getLightDir(objPos)); sum += FLOOR_COLOR * objColor; } else { sum += FLOOR_COLOR * skyColor(); } } return lightSpec + sum / 16.0; } } void main(void) { vec2 st = (2.0 * gl_FragCoord.xy - resolution) / min(resolution.x, resolution.y); vec2 m = (2.0 * mouse - 1.0); vec3 ro = vec3(10.0, 5.0, 10.0); // vec3 ro = vec3(m.x * 50.0, m.y * 20.0, 20.0); vec3 ta = vec3(0.0, -3.0, 0.0); vec3 z = normalize(ta - ro); vec3 up = vec3(0.0, 1.0, 0.0); vec3 x = normalize(cross(z, up)); vec3 y = normalize(cross(x, z)); vec3 rd = normalize(x * st.x + y * st.y + z * 1.5); vec3 c = getColor(ro, rd); gl_FragColor = vec4(pow(c, vec3(1.0 / 2.2)), 1.0); }

glossy reflection