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cpu_launcher.cpp
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cpu_launcher.cpp
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#define _CRT_SECURE_NO_WARNINGS 1
#include <vector>
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#include <iostream>
#include <math.h>
#define _USE_MATH_DEFINES
#include <omp.h>
// Thanks to https://stackoverflow.com/questions/21237905/how-do-i-generate-thread-safe-uniform-random-numbers
#if defined (_MSC_VER) // Visual studio
#define thread_local __declspec( thread )
#elif defined (__GCC__) // GCC
#define thread_local __thread
#endif
#include <random>
#include <time.h>
#include <thread>
#include <chrono>
#include <ctime>
#include <stack>
#define SQR(X) ((X)*(X))
#define NORMED_VEC(X) ((X) / (X).norm())
#ifndef PI
#define PI 3.14159265358979323846
#endif
#define INF (1e9+9)
#include <string>
#include <stdio.h>
#include <algorithm>
#include <vector>
// #define NAIVE
// #define BB
#define ENABLE_BVH
class Vector {
public:
explicit Vector(float x = 0, float y = 0, float z = 0) {
data[0] = x;
data[1] = y;
data[2] = z;
}
float norm2() const {
return data[0] * data[0] + data[1] * data[1] + data[2] * data[2];
}
float norm() const {
return sqrt(norm2());
}
void normalize() {
float n = norm();
data[0] /= n;
data[1] /= n;
data[2] /= n;
}
float operator[](int i) const { return data[i]; };
float& operator[](int i) { return data[i]; };
float data[3];
};
Vector operator+(const Vector& a, const Vector& b) {
return Vector(a[0] + b[0], a[1] + b[1], a[2] + b[2]);
}
Vector operator-(const Vector& a, const Vector& b) {
return Vector(a[0] - b[0], a[1] - b[1], a[2] - b[2]);
}
Vector operator-(const Vector& a) {
return Vector(-a[0], -a[1], -a[2]);
}
Vector operator*(const float a, const Vector& b) {
return Vector(a*b[0], a*b[1], a*b[2]);
}
Vector operator*(const Vector& a, const float b) {
return Vector(a[0]*b, a[1]*b, a[2]*b);
}
// Element wise vector multiplication
Vector operator*(const Vector& a, const Vector& b) {
return Vector(a[0]*b[0], a[1]*b[1], a[2]*b[2]);
}
Vector operator/(const Vector& a, const float b) {
return Vector(a[0] / b, a[1] / b, a[2] / b);
}
float dot(const Vector& a, const Vector& b) {
return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
}
Vector cross(const Vector& a, const Vector& b) {
return Vector(a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0]);
}
class Ray {
public:
Ray(const Vector &O, const Vector &u, float refraction_index = 1.) : O(O), u(u), refraction_index(refraction_index) {};
// ...
Vector O, u;
float refraction_index;
};
class Geometry {
public:
Geometry(const Vector &albedo, int id, bool mirror, float in_refraction_index, float out_refraction_index): albedo(albedo), id(id),
mirror(mirror), in_refraction_index(in_refraction_index), out_refraction_index(out_refraction_index) {}
Geometry(): mirror(0), in_refraction_index(1), out_refraction_index(1) {};
Vector albedo;
int id;
bool mirror;
float in_refraction_index;
float out_refraction_index;
virtual bool intersect(const Ray& r, float &t, Vector &N) { return 0; };
};
/* Start of code derived from Prof Bonnel's code */
class TriangleIndices {
public:
TriangleIndices(int vtxi = -1, int vtxj = -1, int vtxk = -1, int ni = -1, int nj = -1, int nk = -1, int uvi = -1, int uvj = -1, int uvk = -1, int group = -1, bool added = false) : vtxi(vtxi), vtxj(vtxj), vtxk(vtxk), uvi(uvi), uvj(uvj), uvk(uvk), ni(ni), nj(nj), nk(nk), group(group) {
};
int vtxi, vtxj, vtxk; // indices within the vertex coordinates array
int uvi, uvj, uvk; // indices within the uv coordinates array
int ni, nj, nk; // indices within the normals array
int group; // face group
};
class BoundingBox {
public:
Vector mn, mx;
BoundingBox(): mn(Vector(INF, INF, INF)), mx(Vector(-INF, -INF, -INF)) {};
inline void update(const Vector &vec) {
mn[0] = std::min(mn[0], vec[0]);
mn[1] = std::min(mn[1], vec[1]);
mn[2] = std::min(mn[2], vec[2]);
mx[0] = std::max(mx[0], vec[0]);
mx[1] = std::max(mx[1], vec[1]);
mx[2] = std::max(mx[2], vec[2]);
}
inline bool intersect(const Ray &r, float &t) {
float t0x = (mn[0] - r.O[0]) / r.u[0];
float t0y = (mn[1] - r.O[1]) / r.u[1];
float t0z = (mn[2] - r.O[2]) / r.u[2];
float t1x = (mx[0] - r.O[0]) / r.u[0];
float t1y = (mx[1] - r.O[1]) / r.u[1];
float t1z = (mx[2] - r.O[2]) / r.u[2];
if (t0x > t1x) std::swap(t0x, t1x);
if (t0y > t1y) std::swap(t0y, t1y);
if (t0z > t1z) std::swap(t0z, t1z);
return std::min({t1x, t1y, t1z}) > std::max({t0x, t0y, t0z});
}
};
class BVH {
public:
BVH *left, *right;
BoundingBox bb;
int triangle_start, triangle_end;
};
class TriangleMesh: public Geometry {
public:
~TriangleMesh() {}
TriangleMesh() {};
#define between(A, B, C) ((A) <= (B) && (B) <= (C))
// inline bool ray_plane_intersect(const Vector &N, const Vector &A, const Ray &r, float &t) {
// if (dot(r.u, N) == 0) return 0;
// t = dot(A - r.O, N) / dot(r.u, N);
// return 1;
// }
BoundingBox compute_bbox(int triangle_start, int triangle_end) {
BoundingBox bb;
for (int i = triangle_start; i < triangle_end; i++) {
bb.update(vertices[indices[i].vtxi]);
bb.update(vertices[indices[i].vtxj]);
bb.update(vertices[indices[i].vtxk]);
}
return bb;
}
void buildBVH(BVH* cur, int triangle_start, int triangle_end) {
// std::cout << cur << ' ' << triangle_start << ' ' << triangle_end << '\n';
cur->triangle_start = triangle_start;
cur->triangle_end = triangle_end;
cur->left = NULL;
cur->right = NULL;
cur->bb = compute_bbox(triangle_start, triangle_end);
Vector diag = cur->bb.mx - cur->bb.mn;
int max_axis;
if (diag[0] >= diag[1] && diag[0] >= diag[2])
max_axis = 0;
else if (diag[1] >= diag[0] && diag[1] >= diag[2])
max_axis = 1;
else
max_axis = 2;
int pivot = triangle_start;
float split = (cur->bb.mn[max_axis] + cur->bb.mx[max_axis]) / 2;
for (int i = triangle_start; i < triangle_end; i++) {
float cen = (vertices[indices[i].vtxi][max_axis] + vertices[indices[i].vtxj][max_axis] + vertices[indices[i].vtxk][max_axis]) / 3;
if (cen < split) {
std::swap(indices[i], indices[pivot]);
pivot++;
}
}
if (pivot <= triangle_start || pivot >= triangle_end - 1 || triangle_end - triangle_start < 5) {
return;
}
cur->left = new BVH;
cur->right = new BVH;
buildBVH(cur->left, triangle_start, pivot);
buildBVH(cur->right, pivot, triangle_end);
}
bool moller_trumbore(const Vector &A, const Vector &B, const Vector &C, Vector& N, const Ray &r, float &t) {
Vector e1 = B - A;
Vector e2 = C - A;
N = cross(e1, e2);
if (dot(r.u, N) == 0) return 0;
float beta = dot(e2, cross(A - r.O, r.u)) / dot(r.u, N);
float gamma = - dot(e1, cross(A - r.O, r.u)) / dot(r.u, N);
if (!between(0, beta, 1) || !between(0, gamma, 1)) return 0;
t = dot(A - r.O, N) / dot(r.u, N);
return beta + gamma <= 1 && t > 0;
}
bool intersect(const Ray &r, float &t, Vector &N) override {
#ifdef NAIVE
float t_min = INF;
for (auto index: indices) {
float t_cur;
Vector A = vertices[index.vtxi], B = vertices[index.vtxj], C = vertices[index.vtxk];
Vector N_triangle;
bool inter = moller_trumbore(A, B, C, N_triangle, r, t_cur);
if (!inter) continue;
if (t_cur > 0 && t_cur < t_min) {
t_min = t_cur;
N = N_triangle;
}
}
N.normalize();
t = t_min;
return t_min != INF;
#endif
#ifdef BB
float t_tmp;
if (!bvh.bb.intersect(r, t_tmp)) return 0;
float t_min = INF;
for (auto index: indices) {
float t_cur;
Vector A = vertices[index.vtxi], B = vertices[index.vtxj], C = vertices[index.vtxk];
Vector N_triangle;
bool inter = moller_trumbore(A, B, C, N_triangle, r, t_cur);
if (!inter) continue;
if (t_cur > 0 && t_cur < t_min) {
t_min = t_cur;
N = N_triangle;
}
}
N.normalize();
t = t_min;
return t_min != INF;
#endif
#ifdef ENABLE_BVH
float t_tmp;
if (!bvh.bb.intersect(r, t_tmp)) return 0;
std::stack<BVH*> s;
s.push(&bvh);
float t_min = INF;
while(!s.empty()) {
const BVH* cur = s.top();
s.pop();
if (cur->left) {
float t_left, t_right;
bool ok_left = cur->left->bb.intersect(r, t_left);
bool ok_right = cur->right->bb.intersect(r, t_right);
if (ok_left && t_left < t_min) s.push(cur->left);
if (ok_right && t_right < t_min) s.push(cur->right);
} else {
// Leaf
for (int i = cur->triangle_start; i < cur->triangle_end; i++) {
float t_cur;
Vector A = vertices[indices[i].vtxi], B = vertices[indices[i].vtxj], C = vertices[indices[i].vtxk];
Vector N_triangle;
bool inter = moller_trumbore(A, B, C, N_triangle, r, t_cur);
if (!inter) continue;
if (t_cur > 1e-4f && t_cur < t_min) {
t_min = t_cur;
N = N_triangle;
}
}
}
}
N.normalize();
t = t_min;
return t_min != INF;
#endif
return 0;
}
void readOBJ(const char* obj) {
char matfile[255];
char grp[255];
FILE* f;
f = fopen(obj, "r");
if (f == NULL) {
printf("Error opening file!\n");
return;
}
int curGroup = -1;
while (!feof(f)) {
char line[255];
if (!fgets(line, 255, f)) break;
std::string linetrim(line);
linetrim.erase(linetrim.find_last_not_of(" \r\t") + 1);
strcpy(line, linetrim.c_str());
if (line[0] == 'u' && line[1] == 's') {
sscanf(line, "usemtl %[^\n]\n", grp);
curGroup++;
}
if (line[0] == 'v' && line[1] == ' ') {
Vector vec;
Vector col;
if (sscanf(line, "v %f %f %f %f %f %f\n", &vec[0], &vec[1], &vec[2], &col[0], &col[1], &col[2]) == 6) {
col[0] = std::min(1.f, std::max(0.f, col[0]));
col[1] = std::min(1.f, std::max(0.f, col[1]));
col[2] = std::min(1.f, std::max(0.f, col[2]));
vertices.push_back(vec);
vertexcolors.push_back(col);
} else {
sscanf(line, "v %f %f %f\n", &vec[0], &vec[1], &vec[2]);
vec = vec*0.8+Vector(0, -10, 0);
vertices.push_back(vec);
}
bb.update(vec);
}
if (line[0] == 'v' && line[1] == 'n') {
Vector vec;
sscanf(line, "vn %f %f %f\n", &vec[0], &vec[1], &vec[2]);
normals.push_back(vec);
}
if (line[0] == 'v' && line[1] == 't') {
Vector vec;
sscanf(line, "vt %f %f\n", &vec[0], &vec[1]);
uvs.push_back(vec);
}
if (line[0] == 'f') {
TriangleIndices t;
int i0, i1, i2, i3;
int j0, j1, j2, j3;
int k0, k1, k2, k3;
int nn;
t.group = curGroup;
char* consumedline = line + 1;
int offset;
nn = sscanf(consumedline, "%u/%u/%u %u/%u/%u %u/%u/%u%n", &i0, &j0, &k0, &i1, &j1, &k1, &i2, &j2, &k2, &offset);
if (nn == 9) {
if (i0 < 0) t.vtxi = vertices.size() + i0; else t.vtxi = i0 - 1;
if (i1 < 0) t.vtxj = vertices.size() + i1; else t.vtxj = i1 - 1;
if (i2 < 0) t.vtxk = vertices.size() + i2; else t.vtxk = i2 - 1;
if (j0 < 0) t.uvi = uvs.size() + j0; else t.uvi = j0 - 1;
if (j1 < 0) t.uvj = uvs.size() + j1; else t.uvj = j1 - 1;
if (j2 < 0) t.uvk = uvs.size() + j2; else t.uvk = j2 - 1;
if (k0 < 0) t.ni = normals.size() + k0; else t.ni = k0 - 1;
if (k1 < 0) t.nj = normals.size() + k1; else t.nj = k1 - 1;
if (k2 < 0) t.nk = normals.size() + k2; else t.nk = k2 - 1;
indices.push_back(t);
} else {
nn = sscanf(consumedline, "%u/%u %u/%u %u/%u%n", &i0, &j0, &i1, &j1, &i2, &j2, &offset);
if (nn == 6) {
if (i0 < 0) t.vtxi = vertices.size() + i0; else t.vtxi = i0 - 1;
if (i1 < 0) t.vtxj = vertices.size() + i1; else t.vtxj = i1 - 1;
if (i2 < 0) t.vtxk = vertices.size() + i2; else t.vtxk = i2 - 1;
if (j0 < 0) t.uvi = uvs.size() + j0; else t.uvi = j0 - 1;
if (j1 < 0) t.uvj = uvs.size() + j1; else t.uvj = j1 - 1;
if (j2 < 0) t.uvk = uvs.size() + j2; else t.uvk = j2 - 1;
indices.push_back(t);
} else {
nn = sscanf(consumedline, "%u %u %u%n", &i0, &i1, &i2, &offset);
if (nn == 3) {
if (i0 < 0) t.vtxi = vertices.size() + i0; else t.vtxi = i0 - 1;
if (i1 < 0) t.vtxj = vertices.size() + i1; else t.vtxj = i1 - 1;
if (i2 < 0) t.vtxk = vertices.size() + i2; else t.vtxk = i2 - 1;
indices.push_back(t);
} else {
nn = sscanf(consumedline, "%u//%u %u//%u %u//%u%n", &i0, &k0, &i1, &k1, &i2, &k2, &offset);
if (i0 < 0) t.vtxi = vertices.size() + i0; else t.vtxi = i0 - 1;
if (i1 < 0) t.vtxj = vertices.size() + i1; else t.vtxj = i1 - 1;
if (i2 < 0) t.vtxk = vertices.size() + i2; else t.vtxk = i2 - 1;
if (k0 < 0) t.ni = normals.size() + k0; else t.ni = k0 - 1;
if (k1 < 0) t.nj = normals.size() + k1; else t.nj = k1 - 1;
if (k2 < 0) t.nk = normals.size() + k2; else t.nk = k2 - 1;
indices.push_back(t);
}
}
}
consumedline = consumedline + offset;
while (true) {
if (consumedline[0] == '\n') break;
if (consumedline[0] == '\0') break;
nn = sscanf(consumedline, "%u/%u/%u%n", &i3, &j3, &k3, &offset);
TriangleIndices t2;
t2.group = curGroup;
if (nn == 3) {
if (i0 < 0) t2.vtxi = vertices.size() + i0; else t2.vtxi = i0 - 1;
if (i2 < 0) t2.vtxj = vertices.size() + i2; else t2.vtxj = i2 - 1;
if (i3 < 0) t2.vtxk = vertices.size() + i3; else t2.vtxk = i3 - 1;
if (j0 < 0) t2.uvi = uvs.size() + j0; else t2.uvi = j0 - 1;
if (j2 < 0) t2.uvj = uvs.size() + j2; else t2.uvj = j2 - 1;
if (j3 < 0) t2.uvk = uvs.size() + j3; else t2.uvk = j3 - 1;
if (k0 < 0) t2.ni = normals.size() + k0; else t2.ni = k0 - 1;
if (k2 < 0) t2.nj = normals.size() + k2; else t2.nj = k2 - 1;
if (k3 < 0) t2.nk = normals.size() + k3; else t2.nk = k3 - 1;
indices.push_back(t2);
consumedline = consumedline + offset;
i2 = i3;
j2 = j3;
k2 = k3;
} else {
nn = sscanf(consumedline, "%u/%u%n", &i3, &j3, &offset);
if (nn == 2) {
if (i0 < 0) t2.vtxi = vertices.size() + i0; else t2.vtxi = i0 - 1;
if (i2 < 0) t2.vtxj = vertices.size() + i2; else t2.vtxj = i2 - 1;
if (i3 < 0) t2.vtxk = vertices.size() + i3; else t2.vtxk = i3 - 1;
if (j0 < 0) t2.uvi = uvs.size() + j0; else t2.uvi = j0 - 1;
if (j2 < 0) t2.uvj = uvs.size() + j2; else t2.uvj = j2 - 1;
if (j3 < 0) t2.uvk = uvs.size() + j3; else t2.uvk = j3 - 1;
consumedline = consumedline + offset;
i2 = i3;
j2 = j3;
indices.push_back(t2);
} else {
nn = sscanf(consumedline, "%u//%u%n", &i3, &k3, &offset);
if (nn == 2) {
if (i0 < 0) t2.vtxi = vertices.size() + i0; else t2.vtxi = i0 - 1;
if (i2 < 0) t2.vtxj = vertices.size() + i2; else t2.vtxj = i2 - 1;
if (i3 < 0) t2.vtxk = vertices.size() + i3; else t2.vtxk = i3 - 1;
if (k0 < 0) t2.ni = normals.size() + k0; else t2.ni = k0 - 1;
if (k2 < 0) t2.nj = normals.size() + k2; else t2.nj = k2 - 1;
if (k3 < 0) t2.nk = normals.size() + k3; else t2.nk = k3 - 1;
consumedline = consumedline + offset;
i2 = i3;
k2 = k3;
indices.push_back(t2);
} else {
nn = sscanf(consumedline, "%u%n", &i3, &offset);
if (nn == 1) {
if (i0 < 0) t2.vtxi = vertices.size() + i0; else t2.vtxi = i0 - 1;
if (i2 < 0) t2.vtxj = vertices.size() + i2; else t2.vtxj = i2 - 1;
if (i3 < 0) t2.vtxk = vertices.size() + i3; else t2.vtxk = i3 - 1;
consumedline = consumedline + offset;
i2 = i3;
indices.push_back(t2);
} else {
consumedline = consumedline + 1;
}
}
}
}
}
}
}
fclose(f);
}
std::vector<TriangleIndices> indices;
std::vector<Vector> vertices;
std::vector<Vector> normals;
std::vector<Vector> uvs;
std::vector<Vector> vertexcolors;
BoundingBox bb;
BVH bvh;
};
/* End of code derived from Prof Bonnel's code */
class Sphere: public Geometry {
public:
Sphere(const Vector &C, float R, const Vector& albedo, bool mirror = 0, float in_refraction_index = 1., float out_refraction_index = 1.) :
C(C), R(R), Geometry(albedo, id, mirror, in_refraction_index, out_refraction_index) {};
// ...
Vector C;
float R;
bool intersect(const Ray &r, float &t, Vector &N) override {
float delta = SQR(dot(r.u, r.O - C)) - ((r.O - C).norm2() - R*R);
if (delta < 0)
return 0;
float t1 = dot(r.u, C - r.O) - sqrt(delta); // first intersection
float t2 = dot(r.u, C - r.O) + sqrt(delta); // second intersection
if (t2 < 0)
return 0;
t = t1 < 0 ? t2 : t1;
// if (r.u.norm() != 1) {
// std::cout << r.u.norm() << '\n';
// }
N = r.O + t * r.u - C;
N.normalize();
return 1;
}
};
// Thanks to https://stackoverflow.com/questions/21237905/how-do-i-generate-thread-safe-uniform-random-numbers
float uniform(const int &seed) {
static thread_local std::mt19937* generator = nullptr;
if (!generator) generator = new std::mt19937(clock() + seed);
static std::uniform_real_distribution<float> distribution(0, 1);
return distribution(*generator);
}
class Scene {
public:
void addObject(Geometry* s) {
s->id = objects.size();
objects.push_back(s);
}
bool intersect_all(const Ray& r, Vector &P, Vector &N, int &objectId) {
float t_min = INF;
int id_min = -1;
Vector N_min;
for (auto object_ptr: objects) {
float t;
float id = object_ptr->id;
Vector N_tmp;
bool ok = object_ptr->intersect(r, t, N_tmp);
if (ok && t < t_min) {
t_min = t;
id_min = id;
N_min = N_tmp;
}
}
P = r.O + t_min * r.u;
objectId = id_min;
N = N_min;
return id_min != -1;
}
Vector getColor(const Ray& ray, int ray_depth) {
if (ray_depth < 0) return Vector(0., 0., 0.); // terminates recursion at some <- point
Vector P, N;
int sphere_id = -1;
bool inter = intersect_all(ray, P, N, sphere_id);
Vector color;
if (inter) {
if (objects[sphere_id]->mirror) {
// Reflection
float epsilon = 1e-3;
Vector P_adjusted = P + epsilon * N;
Vector new_direction = ray.u - 2 * dot(ray.u, N) * N;
Ray reflected_ray(P_adjusted, new_direction, ray.refraction_index);
return getColor(reflected_ray, ray_depth - 1);
} else if (objects[sphere_id]->in_refraction_index != objects[sphere_id]->out_refraction_index) {
// Refraction
float epsilon = 1e-3;
float refract_ratio;
bool out2in = ray.refraction_index == objects[sphere_id]->out_refraction_index;
if (out2in) { // outside to inside
refract_ratio = objects[sphere_id]->out_refraction_index / objects[sphere_id]->in_refraction_index;
} else { // inside to outside
refract_ratio = objects[sphere_id]->in_refraction_index / objects[sphere_id]->out_refraction_index;
N = -N;
}
if (((out2in && ray.refraction_index > objects[sphere_id]->in_refraction_index) ||
(!out2in && ray.refraction_index > objects[sphere_id]->out_refraction_index)) &&
SQR(refract_ratio) * (1 - SQR(dot(ray.u, N))) > 1) { // total internal reflection
return getColor(Ray(P + epsilon * N, ray.u - 2 * dot(ray.u, N) * N, ray.refraction_index), ray_depth - 1);
}
Vector P_adjusted = P - epsilon * N;
Vector N_component = - sqrt(1 - SQR(refract_ratio) * (1 - SQR(dot(ray.u, N)))) * N;
Vector T_component = refract_ratio * (ray.u - dot(ray.u, N) * N);
Vector new_direction = N_component + T_component;
if (out2in) {
return getColor(Ray(P_adjusted, new_direction, objects[sphere_id]->in_refraction_index), ray_depth - 1);
} else {
return getColor(Ray(P_adjusted, new_direction, objects[sphere_id]->out_refraction_index), ray_depth - 1);
}
} else {
// handle diffuse surfaces
// Get shadow
Vector P_prime;
int sphere_id_shadow;
float epsilon = 1e-3;
Vector P_adjusted = P + epsilon * N;
Vector direct_color, indirect_color;
Vector N_prime;
bool _ = intersect_all(Ray(P_adjusted, NORMED_VEC(L - P_adjusted)), P_prime, N_prime, sphere_id_shadow);
if ((P_prime - P_adjusted).norm2() <= (L - P_adjusted).norm2()) {
// Is shadow
direct_color = Vector(0, 0, 0);
} else {
// Get direct color
Geometry* S = objects[sphere_id];
Vector wlight = L - P;
wlight.normalize();
float l = intensity / (4 * PI * (L - P).norm2()) * std::max(dot(N, wlight), 0.f);
direct_color = l * S->albedo / PI;
}
// Get indirect color by launching rays
unsigned int seed = omp_get_thread_num();
float r1 = uniform(seed);
float r2 = uniform(seed);
float x = cos(2 * PI * r1) * sqrt(1 - r2);
float y = sin(2 * PI * r1) * sqrt(1 - r2);
float z = sqrt(r2);
Vector T1;
if (abs(N[1]) != 0 && abs(N[0]) != 0) {
T1 = Vector(-N[1], N[0], 0);
} else {
T1 = Vector(-N[2], 0, N[0]);
}
T1.normalize();
Vector T2 = cross(N, T1);
Vector random_direction = x * T1 + y * T2 + z * N;
indirect_color = objects[sphere_id]->albedo * getColor(Ray(P_adjusted, random_direction), ray_depth - 1);
// indirect_color = Vector(0, 0, 0);
color = direct_color + indirect_color;
}
}
return color;
}
std::vector<Geometry*> objects;
float intensity = 3e10;
Vector L = Vector(-10., 20., 40.);
};
int main(int argc, char *argv[]) {
if (argc != 3) {
std::cout << "Invalid number of arguments!\nThe first argument is number of rays and the second argument is number of bounces.";
return 0;
}
const int num_rays = atoi(argv[1]), num_bounce = atoi(argv[2]);
auto start_time = std::chrono::system_clock::now();
int W = 512;
int H = 512;
std::default_random_engine generator;
float alpha = PI/3;
Scene s;
// s.addObject(new Sphere(Vector(0, 0, 0), 10, Vector(1., 1., 1.))); // white sphere
// s.addObject(new Sphere(Vector(0, 0, 0), 10, Vector(0., 0., 0.), 0, 1.5, 1)); // refract sphere
// s.addObject(new Sphere(Vector(-20, 0, 0), 10, Vector(0., 0., 0.), 1)); // mirror sphere
// s.addObject(new Sphere(Vector(20, 0, 0), 9, Vector(0., 0., 0.), 0, 1, 1.5)); // inner nested ssphere
// s.addObject(new Sphere(Vector(20, 0, 0), 10, Vector(0., 0., 0.), 0, 1.5, 1)); // outer nested sphere
s.addObject(new Sphere(Vector(0, 0, -1000), 940, Vector(0., 1., 0.))); // green fore wall
s.addObject(new Sphere(Vector(0, -1000, 0), 990, Vector(0., 0., 1.))); // blue floor
s.addObject(new Sphere(Vector(0, 1000, 0), 940, Vector(1., 0., 0.))); // red ceiling
s.addObject(new Sphere(Vector(-1000, 0, 0), 940, Vector(0., 1., 1.))); // cyan left wall
s.addObject(new Sphere(Vector(1000, 0, 0), 940, Vector(1., 1., 0.))); // yellow right wall
s.addObject(new Sphere(Vector(0, 0, 1000), 940, Vector(1., 0., 1.))); // magenta back wall
TriangleMesh* mesh_ptr = new TriangleMesh(); // cat
const char *path = "cadnav.com_model/Models_F0202A090/cat.obj";
mesh_ptr->readOBJ(path);
mesh_ptr->albedo = Vector(0.25, 0.25, 0.25);
mesh_ptr->buildBVH(&(mesh_ptr->bvh), 0, mesh_ptr->indices.size());
s.addObject(mesh_ptr);
std::vector<Vector> vertices;
std::vector<Vector> normals;
std::vector<Vector> uvs;
std::vector<Vector> vertexcolors;
Vector C(0, 0, 55);
std::vector<unsigned char> image(W * H * 3, 0);
float z = -W / (2 * tan(alpha/2));
#pragma omp parallel for schedule(dynamic, 1)
for (int i = 0; i < H; i++) {
for (int j = 0; j < W; j++) {
unsigned int seed = omp_get_thread_num();
Vector u_center((float)j - (float)W / 2 + 0.5, (float)H / 2 - i - 0.5, z);
Vector color_total(0, 0, 0);
for (int t = 0; t < num_rays; t++) {
// Box-muller for anti-aliasing
// float sigma = 2 * pow(10, -1);
float sigma = 0;
float r1 = uniform(seed);
float r2 = uniform(seed);
Vector u = u_center + Vector(sigma * sqrt(-2 * log(r1)) * cos(2 * PI * r2), sigma * sqrt(-2 * log(r1)) * sin(2 * PI * r2), 0);
u.normalize();
Ray r(C, u);
Vector color = s.getColor(r, num_bounce);
color_total = color_total + color;
}
Vector color_avg = color_total / num_rays;
image[(i * W + j) * 3 + 0] = std::min(std::pow(color_avg[0], 1./2.2), 255.);
image[(i * W + j) * 3 + 1] = std::min(std::pow(color_avg[1], 1./2.2), 255.);
image[(i * W + j) * 3 + 2] = std::min(std::pow(color_avg[2], 1./2.2), 255.);
}
}
stbi_write_png("image.png", W, H, 3, &image[0], 0);
auto end_time = std::chrono::system_clock::now();
std::chrono::duration<float> run_time = end_time-start_time;
std::cout << "Rendering time: " << run_time.count() << " s\n";
return 0;
}