diff --git a/pathtracing/reverse/README.md b/pathtracing/reverse/README.md index 45a8302..99bec4f 100644 --- a/pathtracing/reverse/README.md +++ b/pathtracing/reverse/README.md @@ -1,7 +1,7 @@ # Reverse Path Tracing

- +

SDF based ray marching reverse path tracer. Capable of direct and indirect diffuse, specular and refractive ray bounces. \ No newline at end of file diff --git a/pathtracing/reverse/buffer-a-glsl b/pathtracing/reverse/buffer-a-glsl deleted file mode 100644 index b2e8220..0000000 --- a/pathtracing/reverse/buffer-a-glsl +++ /dev/null @@ -1,215 +0,0 @@ - -const int DEPTH = 32; -const int AA = 8; - -const vec2 epsilon = vec2(1e-3, 0); - -const float planeNear = 1e-3; -const float planeFar = 1e2; -const float fov = 82.0; - -const float PI = 3.141592653589793; - -const float pdf = 2.0 * PI; - -#define UNION(a, b) ((a.x) < (b.x) ? (a) : (b)) -#define SDF vec2 - -#define MATERIAL_WHITE 0 -#define MATERIAL_RED 1 -#define MATERIAL_GREEN 2 -#define MATERIAL_BLUE 3 -#define MATERIAL_MIRROR 10 -#define MATERIAL_GLASS 20 -#define MATERIAL_EMISSION 255 - -SDF sdfScene(in vec3 pos) -{ - vec3 q = abs(pos - vec3(0,0.99,-1)) - vec3(0.5, 0.01, 0.5); - SDF li0 = SDF(length(max(q, 0.0)) + min(max(q.x, max(q.y, q.z)), 0.0), MATERIAL_EMISSION); - - SDF sp1 = SDF(length(pos + vec3( 0.5, 0.5, 1)) - 0.5, MATERIAL_WHITE); - SDF sp2 = SDF(abs(length(pos + vec3(-0.5, 0.75, 1)) - 0.25) - epsilon[0], MATERIAL_GLASS); - SDF sp3 = SDF(length(pos + vec3( 0.5,-0.25, 1)) - 0.25, MATERIAL_MIRROR); - - SDF pl0 = SDF( pos.y + 1.0, MATERIAL_WHITE); - SDF pl1 = SDF(-pos.y + 1.0, MATERIAL_WHITE); - SDF pl2 = SDF( pos.x + 1.0, MATERIAL_RED); - SDF pl3 = SDF(-pos.x + 1.0, MATERIAL_GREEN); - SDF pl4 = SDF(-pos.z, MATERIAL_BLUE); - SDF pl5 = SDF( pos.z + 4.1, MATERIAL_WHITE); - - SDF box = UNION(pl0, pl1); - box = UNION(box, pl2); - box = UNION(box, pl3); - box = UNION(box, pl4); - box = UNION(box, pl5); - - box = UNION(box, sp1); - box = UNION(box, sp2); - box = UNION(box, sp3); - - return UNION(li0, box); -} - -vec3 sceneNormal(in vec3 pos) -{ - return normalize(sdfScene(pos)[0] - vec3( - sdfScene(pos + epsilon.xyy)[0], - sdfScene(pos + epsilon.yxy)[0], - sdfScene(pos + epsilon.yyx)[0] - )); -} - -// project vector b onto vector a -vec3 project(in vec3 a, in vec3 b) -{ - return a * (dot(a, b) / dot(a, a)); -} - -// construct a 3D coordinate system with the input up being the "upwards" facing vector -// which will be directly stored in w. -// Mathematically this function will create two non linear vectors of up and generate an orthonormal -// basis using gram-schmidt. -// This function assumes "up" being already normalized -void construct_orthonormal_basis(in vec3 up, out vec3 u, out vec3 v, out vec3 w) -{ - w = up; - - vec3 n2 = normalize(cross(w, vec3(0, 1.0, 1.0))); // build perpendicular vector from w - vec3 n3 = cross(w, n2); // create 2nd vector perpendicular to w and n2 - - // gram schmidt - u = n2 - (project(w, n2)); - v = n3 - project(w, n3) - project(u, n3); -} - -// generate a normalized vector within the bounds of the hemisphere with radius of 1. -// Z-Coordinate will be "upwards". -// radius determines the maximum radius the output vector will have. -// NOTE: shrinkin radius will still result in the output to be normalized -vec3 cosine_weighted_hemisphere() -{ - float u1 = random(); - float u2 = random(); - - float r = sqrt(u1); - float theta = 2.0 * PI * u2; - - float x = r * cos(theta); - float y = r * sin(theta); - - return vec3(x, y, sqrt(1.0 - u1)); -} - -vec3 generate_brdf_ray_direction(in vec3 normal, in vec3 incident) { - vec3 hemisphere = cosine_weighted_hemisphere(); - - vec3 u, v, w; - construct_orthonormal_basis(normal, u, v, w); - - return u * hemisphere.x + v * hemisphere.y + w * hemisphere.z; -} - -vec3 tracePath(in vec3 ro, in vec3 rd) -{ - vec3 col = vec3(0); - vec3 thr = vec3(1); - - for (int k = 0; k < DEPTH; k++) - { - vec3 pos = ro + rd * planeNear; - float t = planeNear; - for (int i = 0; i < 256 && t < planeFar; i++) - { - SDF h = sdfScene(pos); - - if (h[0] < epsilon[0]) - { - vec3 nor = sceneNormal(pos); - - switch(int(h[1])) - { - case MATERIAL_MIRROR: - rd = reflect(rd, nor); - ro = pos - nor * epsilon[0]; - break; - case MATERIAL_GLASS: - if (dot(nor, rd) > random()) - { - rd = refract(rd, -nor, 0.2); - ro = pos + nor * epsilon[0] * 4.0; - } - else - { - rd = reflect(rd, nor); - ro = pos - nor * epsilon[0]; - } - break; - default: - rd = -generate_brdf_ray_direction(nor, rd); - ro = pos - nor * epsilon[0]; - break; - } - - float cosTheta = abs(dot(nor, -rd)) * pdf / PI * 0.6667; - - switch(int(h[1])) - { - case MATERIAL_EMISSION: - col += thr * 10.0; - break; - case MATERIAL_WHITE: - thr *= cosTheta; - break; - case MATERIAL_RED: - thr *= vec3(0.9, 0.1, 0.1) * cosTheta; - break; - case MATERIAL_GREEN: - thr *= vec3(0.1, 0.9, 0.1) * cosTheta; - break; - case MATERIAL_BLUE: - thr *= vec3(0.1, 0.1, 0.9) * cosTheta; - break; - default: - break; - } - break; - } - - t += h[0]; - pos += rd * h[0]; - } - - float m = max(thr.x, max(thr.y, thr.z)); - if (random() > m) - break; - } - return col; -} - -void mainImage(out vec4 fragColor, in vec2 fragCoord) -{ - SEED = (fragCoord.x * fragCoord.y)/iResolution.y + iTime; - - vec3 col = vec3(0); - vec3 ro = vec3(0,0,-3.999); - - // take multiple samples per pixel - // offset each ray direction slightly inside pixel - // in order to anti aliase - for (int i = 0; i < AA; i++, SEED++) - { - vec2 off = vec2(random(), random()) * 0.5; - vec2 uv = (fragCoord + off -0.5 * iResolution.xy) / iResolution.y; - vec3 rd = normalize(vec3(uv, 1.0/tan(fov * 0.008726646259971648))); - - col += tracePath(ro, rd); - } - col /= float(AA); - - vec3 prev = texture(iChannel0, fragCoord.xy/iResolution.xy).rgb; - col = mix(prev, col, 1.0/max(float(iFrame), 1.0)); - - fragColor = vec4(col, 1.0); -} \ No newline at end of file diff --git a/pathtracing/reverse/common.glsl b/pathtracing/reverse/common.glsl deleted file mode 100644 index dd1b1ea..0000000 --- a/pathtracing/reverse/common.glsl +++ /dev/null @@ -1,8 +0,0 @@ - -float SEED = 0.0; - -float random() -{ - SEED ++; - return fract(cos(SEED) * 2474.0); -} \ No newline at end of file diff --git a/pathtracing/reverse/image.glsl b/pathtracing/reverse/image.glsl deleted file mode 100644 index e180b4a..0000000 --- a/pathtracing/reverse/image.glsl +++ /dev/null @@ -1,30 +0,0 @@ -float luminance(vec3 v) -{ - return dot(v, vec3(0.2126f, 0.7152f, 0.0722f)); -} - -vec3 reinhard_jodie(vec3 v) -{ - float l = luminance(v); - vec3 tv = v / (1.0f + v); - return mix(v / (1.0f + l), tv, tv); -} - -float tentKernel(in vec2 xy, in float r) -{ - return (1.0 - abs(xy.x/r)) * (1.0 - abs(xy.y/r)) / (r*r); -} - -float gaussianWeight(in float delta, in float sigma) -{ - return exp(-delta*delta/(2.0 * sigma * sigma)) * 2.5 * sigma; -} - -void mainImage(out vec4 fragColor, in vec2 fragCoord) -{ - vec2 uv = fragCoord.xy/iResolution.xy; - - vec3 color = texture(iChannel0, uv).rgb; - - fragColor = vec4(reinhard_jodie(color), 1); -} \ No newline at end of file