float3 refraction, reflection;\\n\\n refraction = fromOutside ? refract(direction, normal, ratio) : -refract(-direction, normal, ratio);\\n reflection = reflect(direction, normal);\\n\\n // return refraction == float3(0.0, 0.0, 0.0) ? reflection : refraction;\\n return select(refraction == float3(0.0, 0.0, 0.0), reflection, refraction);\\n}\\n\\nbool IntersectRaySphere(float3 origin, float3 direction, Sphere sphere, out float fraction, out float3 normal)\\n{\\n float3 L = origin - sphere.position;\\n float a = dot(direction, direction);\\n float b = 2.0 * dot(L, direction);\\n float c = dot(L, L) - sphere.radius * sphere.radius;\\n float D = b * b - 4 * a * c;\\n\\n if (D < 0.0) return false;\\n\\n float r1 = (-b - sqrt(D)) / (2.0 * a);\\n float r2 = (-b + sqrt(D)) / (2.0 * a);\\n\\n if (r1 > 0.0)\\n fraction = r1;\\n else if (r2 > 0.0)\\n fraction = r2;\\n else\\n return false;\\n\\n normal = normalize(direction * fraction + L);\\n\\n return true;\\n}\\n\\nbool IntersectRayBox(float3 origin, float3 direction, Box box, out float fraction, out float3 normal)\\n{\\n float3 rd = mul(direction, box.rotation);\\n float3 ro = mul((origin - box.position), box.rotation);\\n\\n float3 m = float3(1.0, 1.0, 1.0) / rd;\\n\\n float3 s = float3((rd.x < 0.0) ? 1.0 : -1.0,\\n (rd.y < 0.0) ? 1.0 : -1.0,\\n (rd.z < 0.0) ? 1.0 : -1.0);\\n float3 t1 = m * (-ro + s * box.halfSize);\\n float3 t2 = m * (-ro - s * box.halfSize);\\n\\n float tN = max(max(t1.x, t1.y), t1.z);\\n float tF = min(min(t2.x, t2.y), t2.z);\\n\\n if (tN > tF || tF < 0.0) return false;\\n\\n float3x3 txi = transpose(box.rotation);\\n\\n if (t1.x > t1.y && t1.x > t1.z)\\n normal = txi[0] * s.x;\\n else if (t1.y > t1.z)\\n normal = txi[1] * s.y;\\n else\\n normal = txi[2] * s.z;\\n\\n fraction = tN;\\n\\n return true;\\n}\\n\\nbool CastRay(float3 rayOrigin, float3 rayDirection, out float fraction, out float3 normal, out Material material)\\n{\\n float minDistance = FAR_DISTANCE;\\n\\n for (int i = 0; i < SPHERE_COUNT; i++)\\n {\\n float F;\\n float3 N;\\n if (IntersectRaySphere(rayOrigin, rayDirection, spheres[i], F, N) && F < minDistance)\\n {\\n minDistance = F;\\n normal = N;\\n material = spheres[i].material;\\n }\\n }\\n\\n for (int i = 0; i < BOX_COUNT; i++)\\n {\\n float F;\\n float3 N;\\n if (IntersectRayBox(rayOrigin, rayDirection, boxes[i], F, N) && F < minDistance)\\n {\\n minDistance = F;\\n normal = N;\\n material = boxes[i].material;\\n }\\n }\\n\\n fraction = minDistance;\\n return minDistance != FAR_DISTANCE;\\n}\\n\\nbool IsRefracted(float rand, float3 direction, float3 normal, float opacity, float nIn, float nOut)\\n{\\n float fresnel = FresnelSchlick(nIn, nOut, direction, normal);\\n return opacity > rand && fresnel < rand;\\n}\\n\\nfloat3 TracePath(float3 rayOrigin, float3 rayDirection, float seed, float2 TexCoord)\\n{\\n float3 L = float3(0.0, 0.0, 0.0);\\n float3 F = float3(1.0, 1.0, 1.0);\\n for (int i = 0; i < MAX_DEPTH; i++)\\n {\\n float fraction;\\n float3 normal;\\n Material material;\\n bool hit = CastRay(rayOrigin, rayDirection, fraction, normal, material);\\n if (hit)\\n {\\n float3 newRayOrigin = rayOrigin + fraction * rayDirection;\\n\\n float2 rand = float2(RandomNoise(seed * TexCoord.xy), seed * RandomNoise(TexCoord.yx));\\n float3 hemisphereDistributedDirection = NormalOrientedHemispherePoint(rand, normal);\\n\\n float3 randomVec = float3(\\n RandomNoise(sin(seed * TexCoord.xy)),\\n RandomNoise(cos(seed * TexCoord.xy)),\\n RandomNoise(sin(seed * TexCoord.yx))\\n );\\n randomVec = normalize(2.0 * randomVec - 1.0);\\n\\n

@compute.toys