precision mediump float; const int MAX_STEP = 20; const float MAX_DISTANCE = 1.000000; const float EPSILON = 0.001000; // float halfDivEpsilon = 0.5 / EPSILON; const float halfDivEpsilon = 500.000000; const float SAMPLES = 64.000000; const float TWO_PI = 6.283185; const float twoPIDivSamples = 0.098175; const float oneDivSamples = 0.015625; const float BIAS = 0.01; const float MAX_DEPTH = 2.0; uniform float u_counter; uniform vec2 u_mouse; uniform vec2 u_resolution; const vec3 BLACK = vec3(0.0,0.0,0.0); const vec3 WHITE = vec3(1.0,1.0,1.0); struct ssDot{float sd; float reflectivity; float eta; vec3 emission; vec3 absorption;}; ssDot unionOp(ssDot a, ssDot b){ if (a.sd < b.sd){ return a; }else{ return b; } } ssDot intersectOp(ssDot a, ssDot b) { ssDot r; if (a.sd > b.sd){ r = b; r.sd = a.sd; }else{ r = a; r.sd = b.sd; } return r; } ssDot subtractOp(ssDot a, ssDot b) { ssDot r = a; if (a.sd > -b.sd){ r.sd = a.sd; }else{ r.sd = -b.sd; } return r; } ssDot complementOp(ssDot a) { a.sd = -a.sd; return a; } float fresnel(float cosi, float cost, float etai,float etat) { float rs = (etat * cosi - etai * cost) / (etat * cosi + etai * cost); float rp = (etai * cosi - etat * cost) / (etai * cosi + etat * cost); return (rs * rs + rp * rp) * 0.7; } vec3 beerLambert(vec3 a, float d) { return vec3(exp(-a.x * d), exp(-a.y * d), exp(-a.z * d)); } float theta = 0.785398; float costheta = 0.707107, sintheta = sin(0.707107); float box(float x, float y, float cx, float cy, float theta, float sx, float sy) { //x += step(0.0,sin(y*10.0)); float dx = abs((x - cx) * costheta + (y - cy) * sintheta) - sx; float dy = abs((y - cy) * costheta - (x - cx) * sintheta) - sy; float ax = max(dx, 0.0), ay = max(dy, 0.0); return min(max(dx, dy), 0.0) + sqrt(ax * ax + ay * ay); } float box2(float x, float y, float cx, float cy, float theta, float sx, float sy) { float dx = abs(x - cx) - sx; float dy = abs(y - cy) - sy; float ax = max(dx, 0.0), ay = max(dy, 0.0); return min(max(dx, dy), 0.0) + sqrt(ax * ax + ay * ay); } float circle(float x,float y,float xc,float yc,float r){ return sqrt((x-xc)*(x-xc)+(y-yc)*(y-yc))-r; } ssDot scene(float x,float y){ ssDot hero = ssDot(circle(x,y,u_mouse.x,u_mouse.y, 0.05), 1.0, 0.0, vec3(2.0, 2.0, 2.0), vec3(4.0, 4.0, 4.0)); // hero ssDot tv = ssDot(box2(x,y,-1.0,0.0,0.0,0.1,0.5), 0.5, 0.3, vec3(0.4,0.1,0.45), vec3(0.5)); //==BOX== ssDot th = ssDot(box2(x,y,-1.0,-0.1,0.0,0.4,0.1), 0.5, 0.3, vec3(0.4,0.1,0.45), vec3(0.5)); //==BOX== ssDot t = unionOp(tv,th); ssDot ub = ssDot( box2(x,y,0.0,0.0,0.0,0.3,0.25), .7, 0.7, BLACK, vec3(0.0, 0.0, 3.0)); ssDot uc = ssDot(circle(x,y,0.0,-0.2, 0.3), .7, 0.7, BLACK, vec3(0.0, 0.0, 3.0)); //================================================================================================================================================= ssDot usb = ssDot(box2(x,y,0.0,0.1,0.0,0.1,0.30), 0.0, 0.0, BLACK, BLACK); ssDot usc = ssDot(circle(x,y,0.0,-0.2, 0.1), 0.0, 0.0, BLACK, BLACK); //================================================================================================================================================= ssDot u = subtractOp(unionOp(ub, uc),unionOp(usb, usc)); ssDot x1 = ssDot(box(x,y,1.0,-0.1,0.0,0.1,0.4), 1.4, 0.0, vec3(0.5,0.0,0.0), vec3(1.0, 1.5, 1.1)); //==BOX== ssDot x2 = ssDot(box(x,y,1.0,-0.1,0.0,0.4,0.1), 1.4, 0.0, vec3(0.5,0.0,0.0), vec3(1.0, 1.5, 1.1)); //==BOX== ssDot xch = unionOp(x1,x2); return unionOp(unionOp(unionOp(t, u), hero), xch); } void gradient(float x, float y, out float nx, out float ny) { nx = (scene(x + EPSILON, y).sd - scene(x - EPSILON, y).sd) * halfDivEpsilon; ny = (scene(x, y + EPSILON).sd - scene(x, y - EPSILON).sd) * halfDivEpsilon; } void reflectX(float ix, float iy, float nx, float ny, out float rx, out float ry) { float idotn2 = (ix * nx + iy * ny) * 2.0; rx = ix - idotn2 * nx; ry = iy - idotn2 * ny; } bool refractX(float ix, float iy, float nx, float ny, float eta, out float rx, out float ry) { float idotn = ix * nx + iy * ny; float k = 1.0 - eta * eta * (1.0 - idotn * idotn); if (k < 0.0) return false; // Total internal reflection float a = eta * idotn + sqrt(k); rx = eta * ix - a * nx; ry = eta * iy - a * ny; return true; } vec3 trace4(float ox, float oy, float dx, float dy, float depth) { float t = 0.001; float sgn = scene(ox, oy).sd > 0.0 ? 1.0 : -1.0; for (int i = 0; i < MAX_STEP; i++) { if (t >= MAX_DISTANCE){break;} float x = ox + dx * t, y = oy + dy * t; ssDot r = scene(x, y); if (r.sd * sgn < EPSILON) { vec3 sum = r.emission; // if (depth < MAX_DEPTH && r.eta > 0.0) { // float nx, ny, rx, ry, refl = r.reflectivity; // gradient(x, y, nx, ny); // float s = 1.0 / (nx * nx + ny * ny); // nx *= sgn * s; // ny *= sgn * s; // if (r.eta > 0.0) { // if (refract(dx, dy, nx, ny, sgn < 0.0 ? r.eta : 1.0 / r.eta, rx, ry)) { // float cosi = -(dx * nx + dy * ny); // float cost = -(rx * nx + ry * ny); // refl = sgn < 0.0 ? fresnel(cosi, cost, r.eta, 1.0) : fresnel(cosi, cost, 1.0, r.eta); // refl = max(min(refl, 1.0), 0.0); // //sum = colorAdd(sum, colorScale(trace(x - nx * BIAS, y - ny * BIAS, rx, ry, depth + 1.0), 1.0 - refl)); // } // else // refl = 1.0; // Total internal reflection // } // if (refl > 0.0) { // reflect(dx, dy, nx, ny, rx, ry); // //sum = colorAdd(sum, colorScale(trace(x + nx * BIAS, y + ny * BIAS, rx, ry, depth + 1.0), refl)); // } // } return sum * beerLambert(r.absorption, t); } t += r.sd * sgn; } return BLACK; } vec3 trace3(float ox, float oy, float dx, float dy, float depth) { float t = 0.001; float sgn = scene(ox, oy).sd > 0.0 ? 1.0 : -1.0; for (int i = 0; i < MAX_STEP; i++) { if (t >= MAX_DISTANCE){break;} float x = ox + dx * t, y = oy + dy * t; ssDot r = scene(x, y); if (r.sd * sgn < EPSILON) { vec3 sum = r.emission; // if (depth < MAX_DEPTH && r.eta > 0.0) { // float nx, ny, rx, ry, refl = r.reflectivity; // gradient(x, y, nx, ny); // float s = 1.0 / (nx * nx + ny * ny); // nx *= sgn * s; // ny *= sgn * s; // if (r.eta > 0.0) { // if (refract(dx, dy, nx, ny, sgn < 0.0 ? r.eta : 1.0 / r.eta, rx, ry)) { // float cosi = -(dx * nx + dy * ny); // float cost = -(rx * nx + ry * ny); // refl = sgn < 0.0 ? fresnel(cosi, cost, r.eta, 1.0) : fresnel(cosi, cost, 1.0, r.eta); // refl = max(min(refl, 1.0), 0.0); // sum = colorAdd(sum, colorScale(trace4(x - nx * BIAS, y - ny * BIAS, rx, ry, depth + 1.0), 1.0 - refl)); // } // else // refl = 1.0; // Total internal reflection // } // if (refl > 0.0) { // reflect(dx, dy, nx, ny, rx, ry); // sum = colorAdd(sum, colorScale(trace4(x + nx * BIAS, y + ny * BIAS, rx, ry, depth + 1.0), refl)); // } // } return sum * beerLambert(r.absorption, t); } t += r.sd * sgn; } return BLACK; } vec3 trace2(float ox, float oy, float dx, float dy, float depth) { float t = 0.001; float sgn = scene(ox, oy).sd > 0.0 ? 1.0 : -1.0; for (int i = 0; i < MAX_STEP; i++) { if (t >= MAX_DISTANCE){break;} float x = ox + dx * t, y = oy + dy * t; ssDot r = scene(x, y); if (r.sd * sgn < EPSILON) { vec3 sum = r.emission; if (depth < MAX_DEPTH && r.eta > 0.0) { //depth++; float nx, ny, rx, ry, refl = r.reflectivity; gradient(x, y, nx, ny); float s = 1.0 / (nx * nx + ny * ny); nx *= sgn * s; ny *= sgn * s; if (r.eta > 0.0) { if (refractX(dx, dy, nx, ny, sgn < 0.0 ? r.eta : 1.0 / r.eta, rx, ry)) { float cosi = -(dx * nx + dy * ny); float cost = -(rx * nx + ry * ny); refl = sgn < 0.0 ? fresnel(cosi, cost, r.eta, 1.0) : fresnel(cosi, cost, 1.0, r.eta); refl = max(min(refl, 1.0), 0.0); sum = sum + trace3(x - nx * BIAS, y - ny * BIAS, rx, ry, depth + 1.0)*( 1.0 - refl); } else refl = 1.0; // Total internal reflection } if (refl > 0.0) { //reflect(dx, dy, nx, ny, rx, ry); sum = sum + trace3(x + nx * BIAS, y + ny * BIAS, rx, ry, depth + 1.0) * refl; } } return sum * beerLambert(r.absorption, t); } t += r.sd * sgn; } return BLACK; } vec3 trace(float ox, float oy, float dx, float dy, float depth) { float t = 0.001; float sgn = scene(ox, oy).sd > 0.0 ? 1.0 : -1.0; for (int i = 0; i < MAX_STEP; i++) { if (t >= MAX_DISTANCE){break;} float x = ox + dx * t, y = oy + dy * t; ssDot r = scene(x, y); if (r.sd * sgn < EPSILON) { vec3 sum = r.emission; if (depth < MAX_DEPTH && r.eta > 0.0) { //depth++; float nx, ny, rx, ry, refl = r.reflectivity; gradient(x, y, nx, ny); float s = 1.0 / (nx * nx + ny * ny); nx *= sgn * s; ny *= sgn * s; if (r.eta > 0.0) { if (refractX(dx, dy, nx, ny, sgn < 0.0 ? r.eta : 1.0 / r.eta, rx, ry)) { float cosi = -(dx * nx + dy * ny); float cost = -(rx * nx + ry * ny); refl = sgn < 0.0 ? fresnel(cosi, cost, r.eta, 1.0) : fresnel(cosi, cost, 1.0, r.eta); refl = max(min(refl, 1.0), 0.0); sum = sum + trace2(x - nx * BIAS, y - ny * BIAS, rx, ry, depth + 1.0) * (1.0 - refl); } else refl = 1.0; // Total internal reflection } if (refl > 0.0) { reflectX(dx, dy, nx, ny, rx, ry); sum = sum + trace2(x + nx * BIAS, y + ny * BIAS, rx, ry, depth + 1.0) * refl; } } return sum * beerLambert(r.absorption, t); } t += r.sd * sgn; } return BLACK; } float rand(float i){ return sin(i/10.0); } vec3 sampleFun(float x, float y) { vec3 sum = BLACK; for (float i = 0.0; i < SAMPLES; i++) { float a =i * twoPIDivSamples; sum = sum + trace(x, y, sin(a), cos(a), 0.0); if (sum.x > 100.0){return sum/i;} } return sum * oneDivSamples; } void main() { // Normalized pixel coordinates (from 0 to 1) //vec2 uv = gl_FragCoord.xy/u_resolution.xy; vec2 uv = (2.*gl_FragCoord.xy-u_resolution.xy ) / u_resolution.y; vec3 col = sampleFun(uv.x, uv.y); // Output to screen gl_FragColor = vec4(col,1.0); }

xach's Shaders (1)