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demorso.cpp
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demorso.cpp
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#define _USE_MATH_DEFINES
#include <cassert>
#include <math.h>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <string>
#include <iostream>
#if defined(__APPLE__)
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#include <GLUT/glut.h>
#else
#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__)
#include <windows.h>
#endif
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>
#endif
//#include <vld.h>
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"
struct vec3;
// Pseudocolor mapping of a scalar value
// http://www.kennethmoreland.com/color-maps/, CoolWarmFloat33.csv
float pscols[4 * 33] = { // 33 colors RGB
0,0.2298057,0.298717966,0.753683153, 0.03125,0.26623388,0.353094838,0.801466763,
0.0625,0.30386891,0.406535296,0.84495867, 0.09375,0.342804478,0.458757618,0.883725899,
0.125,0.38301334,0.50941904,0.917387822, 0.15625,0.424369608,0.558148092,0.945619588,
0.1875,0.46666708,0.604562568,0.968154911, 0.21875,0.509635204,0.648280772,0.98478814,
0.25,0.552953156,0.688929332,0.995375608, 0.28125,0.596262162,0.726149107,0.999836203,
0.3125,0.639176211,0.759599947,0.998151185, 0.34375,0.681291281,0.788964712,0.990363227,
0.375,0.722193294,0.813952739,0.976574709, 0.40625,0.761464949,0.834302879,0.956945269,
0.4375,0.798691636,0.849786142,0.931688648, 0.46875,0.833466556,0.860207984,0.901068838,
0.5,0.865395197,0.86541021,0.865395561, 0.53125,0.897787179,0.848937047,0.820880546,
0.5625,0.924127593,0.827384882,0.774508472, 0.59375,0.944468518,0.800927443,0.726736146,
0.625,0.958852946,0.769767752,0.678007945, 0.65625,0.96732803,0.734132809,0.628751763,
0.6875,0.969954137,0.694266682,0.579375448, 0.71875,0.966811177,0.650421156,0.530263762,
0.75,0.958003065,0.602842431,0.481775914, 0.78125,0.943660866,0.551750968,0.434243684,
0.8125,0.923944917,0.49730856,0.387970225, 0.84375,0.89904617,0.439559467,0.343229596,
0.875,0.869186849,0.378313092,0.300267182, 0.90625,0.834620542,0.312874446,0.259301199,
0.9375,0.795631745,0.24128379,0.220525627, 0.96875,0.752534934,0.157246067,0.184115123,
1.0,0.705673158,0.01555616,0.150232812
};
// Structure to compute variance
struct SVAR
{
unsigned int cnt; // the number of samples taken to compute statistics
double mean; // mean value1
double M2; // sum for variance1
void Reset() { cnt = 0; mean = M2 = 0; }
// Statistical support
SVAR() { Reset(); }
// add a single sample
void Update(const double newSampleValue)
{
cnt++;
double delta = newSampleValue - mean;
mean += delta / (double)cnt;
M2 += delta * (newSampleValue - mean);
}
// It returns unbiased sample variance (so not for finite population)
double Evaluate() { return (double)M2 / ((double)cnt - 1); }
};
const double epsilon = 1e-9; // Small value
const int rainbowPSC = 0; // 0 .. use CoolWarm mapping, 1 .. use rainbow color mapping
const int showBargraph = 1; // 0/1 .. dont use/use bargraph on the right for color mapping
enum Show { DIFF, WEIGHT, WEIGHT_PSEUDOCOLOR };
const Show showFlag = WEIGHT_PSEUDOCOLOR;
// The cost of sampling - should be measured and set
double costBRDF = 1.0, costLight = 1.0, referenceEfficiency = 1.0;
int nIterations = 1; // how many iterations to render
int nTotalSamples = 128; // samples in one render iteration - should be even number
int PT_MAX_DEPTH = 50; // max path tracing depth - should not be used because of russian roulette
// fast and ugly way of deciding which reflection happened
int REFL_DIFFUSE = 1;
int REFL_SPEC = 2;
int REFL_TYPE_PLACEHOLDER;
// Compute random number in range [0,1], uniform distribution
double drandom() { return (double)rand() / RAND_MAX; }
template<typename T>
T Clamp(T value, T lowerBound, T upperBound)
{
if (value < lowerBound) return lowerBound;
else if (value > upperBound) return upperBound;
else return value;
}
// -------------------- VECTORS
// Vector 3D
struct vec3
{
double x, y, z;
vec3() { x = y = z = 0; }
vec3(double x0, double y0, double z0 = 0) { x = x0; y = y0; z = z0; }
vec3 operator*(double a) const { return vec3(x * a, y * a, z * a); }
vec3 operator*(const vec3 r) const { return vec3(x * r.x, y * r.y, z * r.z); }
vec3 operator/(const double r) const
{
if (fabs(r) > epsilon)
return vec3(x / r, y / r, z / r);
else
return vec3(0, 0, 0);
}
vec3 operator+(const vec3& v) const { return vec3(x + v.x, y + v.y, z + v.z); }
vec3 operator-(const vec3& v) const { return vec3(x - v.x, y - v.y, z - v.z); }
void operator+=(const vec3& v) { x += v.x, y += v.y, z += v.z; }
void operator*=(double a) { x *= a, y *= a, z *= a; }
double length() const { return sqrt(x * x + y * y + z * z); }
vec3 normalize() const
{
double l = length();
if (l > epsilon)
return (*this) / l;
else
return vec3(0, 0, 0);
}
double average() { return (x + y + z) / 3; }
};
// dot product of two vectors
double dot(const vec3& v1, const vec3& v2)
{
return (v1.x * v2.x + v1.y * v2.y + v1.z * v2.z);
}
// cross product of two vectors
vec3 cross(const vec3& v1, const vec3& v2)
{
return vec3(v1.y * v2.z - v1.z * v2.y, v1.z * v2.x - v1.x * v2.z, v1.x * v2.y - v1.y * v2.x);
}
// reflection of vector around normal
vec3 reflect(const vec3& N, const vec3& L)
{
return (N * (2.0 * dot(N, L))) - L;
}
// computes lumimance from RGB vector
float lumimance(const float r, const float g, const float b)
{
return 0.2126f * r + 0.7152f * g + 0.0722f * b;
}
// return theta (spherical coords) from some vector
inline float SphericalTheta(const vec3& v) {
return acos(Clamp(v.y, -1.0, 1.0));
}
// return phi (spherical coords) from some vector
inline float SphericalPhi(const vec3& v) {
float p = atan2(v.z, v.x) - M_PI/2.0f;
return (p < 0) ? (p + 2.0f * M_PI) : p;
}
struct Distribution1D
{
float* func;
float* cdf;
float funcInt, invFuncInt, invCount;
int count;
Distribution1D(float* f, int n)
{
func = new float[n];
cdf = new float[n + 1];
count = n;
memcpy(func, f, n * sizeof(float));
ComputeStep1dCDF(func, n, &funcInt, cdf);
invFuncInt = 1.0f / funcInt;
invCount = 1.0f / count;
}
~Distribution1D()
{
delete[] func;
delete[] cdf;
}
void ComputeStep1dCDF(float* f, int nSteps, float* c, float* cdf)
{
// Init first to 0 to be able to compute from it
cdf[0] = 0.0;
for (int i = 1; i < nSteps + 1; i++) {
cdf[i] = cdf[i - 1] + f[i - 1] / nSteps;
}
// save sum
*c = cdf[nSteps];
// normalize
for (int i = 0; i < nSteps + 1; i++) {
cdf[i] = cdf[i] / *c;
}
}
float Sample(float u, float* pdf)
{
// std version of binary search of first element that is not less than value
float* ptr = std::lower_bound(cdf, cdf + count + 1, u);
// index of that pointer in array
int offset = (int)(ptr - cdf - 1);
u = (u - cdf[offset]) / (cdf[offset + 1] - cdf[offset]);
*pdf = func[offset] * invFuncInt;
return offset + u;
}
};
// -------------------- MATERIALS
// The definition of material surface (BRDF + emission)
struct Material
{
vec3 Le; // the emmited power
vec3 diffuseAlbedo; // albedo for diffuse component
vec3 specularAlbedo; // albedo for specular component
double shininess;
Material() {
Le = vec3(0.0, 0.0, 0.0);
shininess = 0;
}
// Evaluate the BRDF given normal, view direction (outgoing) and light direction (incoming)
vec3 BRDF(const vec3& N, const vec3& V, const vec3& L)
{
vec3 brdf(0, 0, 0);
double cosThetaL = dot(N, L);
double cosThetaV = dot(N, V);
if (cosThetaL <= epsilon || cosThetaV <= epsilon)
return brdf;
brdf = diffuseAlbedo / M_PI; // diffuse part
vec3 R = N * (dot(N, L) * 2.0) - L;
double cosPhi = dot(V, R);
if (cosPhi <= 0)
return brdf; // farther by PI/2 from reflected direction
// max-Phong specular BRDF: symmetric and energy conserving
return brdf + specularAlbedo * ((shininess + 1.0) / 2.0 / M_PI * pow(cosPhi, shininess) / fmax(cosThetaL, cosThetaV));
}
// BRDF.cos(theta) importance sampling for input normal, outgoing direction
bool sampleDirection(const vec3& N, const vec3& V, vec3& L, int& type)
{ // output - the incoming light direction
L = vec3(0, 0, 0);
// TODO: change to only two randoms
const double randomType = drandom();
const double um = drandom();
const double vm = drandom();
vec3 koeffs;
if (randomType < diffuseAlbedo.average()) {
const double alpham = acos(sqrt(um));
const double thetam = 2.0 * M_PI * vm;
koeffs.x = sin(alpham) * cos(thetam);
koeffs.y = sin(alpham) * sin(thetam);
koeffs.z = cos(alpham);
const vec3 w = vec3(2.0 * drandom() - 1.0, 2.0 * drandom() - 1.0, 2.0 * drandom() - 1.0).normalize();
vec3 k = N.normalize();
vec3 i = cross(N, w).normalize();
vec3 j = cross(i, k).normalize();
const vec3 Lm = i * koeffs.x + j * koeffs.y + k * koeffs.z;
if (dot(N, Lm) < 0)
return false;
type = REFL_DIFFUSE;
L = Lm;
} else if (randomType < (diffuseAlbedo.average() + specularAlbedo.average())) {
const double alpham = acos(pow(um, 1 / (shininess + 1)));
const double thetam = 2.0 * M_PI * vm;
koeffs.x = sin(alpham) * cos(thetam);
koeffs.y = sin(alpham) * sin(thetam);
koeffs.z = cos(alpham);
const vec3 k = V.normalize();
//const vec3 k = reflect(N, V).normalize();
const vec3 i = cross(V, N).normalize();
const vec3 j = cross(i, k).normalize();
const vec3 Rm = i * koeffs.x + j * koeffs.y + k * koeffs.z;
const vec3 Lm = (N * dot(N, Rm) * 2.0 - Rm).normalize();
if (dot(N, Lm) < 0)
return false;
type = REFL_SPEC;
L = Lm;
} else {
return false;
}
return true; // error - no value
}
// Evaluate the probability given input normal, view (outgoing) direction and incoming light direction
double sampleProb(const vec3& N, const vec3& V, const vec3& L)
{
double p = 0.0;
p += diffuseAlbedo.average() * max(0.0, dot(L, N)) / M_PI;
p += specularAlbedo.average() * ((shininess + 1.0) / (2.0 * M_PI)) * pow(max(0.0, dot(V, reflect(N, L))), shininess);
return p;
}
};
// Material used for light source
struct LightMaterial : Material
{
LightMaterial(vec3 _Le) { Le = _Le; }
};
// Material used for objects, given how much is reflective/shiny
struct TableMaterial : Material
{
TableMaterial(double shine)
{
shininess = shine;
// or both at .5
diffuseAlbedo = vec3(0.8, 0.8, 0.8);
specularAlbedo = vec3(0.05, 0.05, 0.05);
}
};
struct GeneralMaterial : Material
{
GeneralMaterial(double shine, vec3 color, float diffuseConst, float specularConst)
{
shininess = shine;
diffuseAlbedo = color * diffuseConst;
specularAlbedo = color * specularConst;
}
};
// Structure for a ray
struct Ray
{
vec3 start, dir;
Ray(const vec3& _start, const vec3& _dir) { start = _start; dir = _dir.normalize(); }
};
class Intersectable;
// Structure to store the result of ray tracing
struct Hit
{
double t;
vec3 position;
vec3 normal;
Material* material;
Intersectable* object;
Hit() { t = -1; }
};
// Abstract 3D object
struct Intersectable
{
Material* material;
double power;
virtual Hit intersect(const Ray& ray) = 0;
virtual double pointSampleProb(double totalPower)
{
printf("Point sample on table\n");
return 0;
}
};
// Rectangle 2D in 3D space
class Rect : public Intersectable
{
// anchor point, normal,
vec3 r0, normal, right, forward;
double width, height; // size
public:
Rect(vec3 _r0, vec3 _r1, vec3 _r2,
double _width, double _height, Material* mat)
{
r0 = _r0;
vec3 L = _r1 - r0;
vec3 V = _r2 - r0;
// compute normal
normal = (L.normalize() + V.normalize()).normalize();
material = mat;
power = 0; // default - does not emit light
width = _width; height = _height;
// recompute directions to get rectangle
right = cross(vec3(0, 0, 1), normal).normalize();
forward = cross(normal, right).normalize();
}
// Compute intersection between a ray and the rectangle
Hit intersect(const Ray& ray)
{
Hit hit;
double denom = dot(normal, ray.dir);
if (fabs(denom) > epsilon) {
hit.t = dot(normal, r0 - ray.start) / denom;
if (hit.t < 0) return hit;
hit.position = ray.start + ray.dir * hit.t;
double x = dot(hit.position - r0, right);
double y = dot(hit.position - r0, forward);
if (fabs(x) > width || fabs(y) > height) {
hit.t = -1;
return hit;
}
hit.normal = normal;
hit.position = ray.start + ray.dir * hit.t;
hit.material = material;
hit.object = this;
}
return hit;
}
};
// Sphere used as light source
struct Sphere : public Intersectable
{
vec3 center;
double radius;
Sphere(const vec3& cent, double rad, Material* mat)
{
const double targetPower = 60;
center = cent; radius = rad;
material = mat;
power = material->Le.average() * (4 * radius * radius * M_PI) * M_PI;
if (power > 0.0f) {
material->Le = material->Le * (targetPower / power);
}
power = targetPower;
}
Hit intersect(const Ray& r)
{
Hit hit;
vec3 dist = r.start - center;
double b = dot(dist, r.dir) * 2.0;
double a = dot(r.dir, r.dir);
double c = dot(dist, dist) - radius * radius;
double discr = b * b - 4.0 * a * c;
if (discr < 0) return hit;
double sqrt_discr = sqrt(discr);
double t1 = (-b + sqrt_discr) / 2.0 / a;
double t2 = (-b - sqrt_discr) / 2.0 / a;
if (t1 <= 0 && t2 <= 0) return hit;
if (t1 <= 0 && t2 > 0)
hit.t = t2;
else
if (t2 <= 0 && t1 > 0)
hit.t = t1;
else
if (t1 < t2)
hit.t = t1;
else
hit.t = t2;
hit.position = r.start + r.dir * hit.t;
hit.normal = (hit.position - center) / radius;
hit.material = material;
hit.object = this;
return hit;
}
// find a random point with uniform distribution on that half sphere, which can be visible
void sampleUniformPoint(const vec3& illuminatedPoint, vec3& point, vec3& normal)
{
do {
// uniform in a cube of edge size 2
normal = vec3(drandom() * 2 - 1, drandom() * 2 - 1, drandom() * 2 - 1);
if (dot(illuminatedPoint - center, normal) < 0) continue; // ignore surely non visible points
} while (dot(normal, normal) > 1); // finish if the point is in the unit sphere
normal = normal.normalize(); // project points onto the surface of the unit sphere
point = center + normal * radius; // project onto the real sphere
}
double pointSampleProb(double totalPower)
{
return power / totalPower / (4 * radius * radius * M_PI);
}
};
// -------------------- LIGHTS
struct Light
{
vec3 normal;
// get sample
virtual vec3 sampleLight(const vec3& point, vec3* wi, float* pdf) = 0;
// probability of sample
virtual float sampleProbability(const vec3& point, const vec3& wi, float totalPower) = 0;
// get ilumination at dir
virtual vec3 getIlumination(vec3 dir) = 0;
};
// The light source represented by a sphere
struct SphereLight : Light
{
Sphere* sphere;
vec3 point;
SphereLight(Sphere* _sphere, vec3 _point, vec3 _normal) {
sphere = _sphere;
point = _point;
normal = _normal;
}
vec3 sampleLight(const vec3& point, vec3* wi, float* pdf) {
return sphere->material->Le;
}
float sampleProbability(const vec3& point, const vec3& wi, float totalPower) {
return sphere->pointSampleProb(totalPower);
}
vec3 getIlumination(vec3 dir) {
return sphere->material->Le;
}
};
struct InfiniteAreaLight : Light
{
float* img;
float* luminanceImg;
int nu;
int nv;
int n;
vec3 point;
bool debug = false;
Distribution1D* uDistrib;
Distribution1D** vDistribs;
InfiniteAreaLight(const char* path)
{
img = stbi_loadf(path, &nu, &nv, &n, 0);
luminanceImg = new float[nu * nv];
RGBToLuminanceImage(img, nu, nv, luminanceImg);
// calculate sin value for every row of image for later weighting
float* sinVals = new float[nv * sizeof(float)];
for (int i = 0; i < nv; i++) {
sinVals[i] = sinf(M_PI * float(i + 0.5f) / float(nv));
}
// Buffer for storing sin weighted luminance values
float* func = new float[max(nu, nv)];
vDistribs = new Distribution1D * [nu];
for (int u = 0; u < nu; ++u) {
for (int v = 0; v < nv; ++v) {
func[v] = luminanceImg[v * nu + u] * sinVals[v];
}
vDistribs[u] = new Distribution1D(func, nv);
}
for (int u = 0; u < nu; ++u) {
func[u] = vDistribs[u]->funcInt;
}
uDistrib = new Distribution1D(func, nu);
}
~InfiniteAreaLight()
{
stbi_image_free(img);
delete[] luminanceImg;
}
vec3 sampleLight(const vec3& point, vec3* wi, float* pdf) {
float u;
float v;
return Sample(wi, pdf, &u, &v);
}
float sampleProbability(const vec3& point, const vec3& wi, float totalPower) {
return pdf(point, wi);
}
vec3 getIlumination(vec3 dir) {
return sampleMapFromDirection(dir, vec3(1, 0, 0));
}
vec3 Sample(vec3* wi, float* pdf, float* uOpt, float* vOpt)
{
const float u1 = drandom();
const float u2 = drandom();
float pdfs[2];
float fu = uDistrib->Sample(u1, &pdfs[0]);
int u = Clamp((int)fu, 0, uDistrib->count - 1);
float fv = vDistribs[u]->Sample(u2, &pdfs[1]);
float theta = fv * vDistribs[u]->invCount * M_PI;
float phi = fu * uDistrib->invCount * 2.0f * M_PI + M_PI / 2.0f;
*wi = vec3(sin(theta) * cos(phi), cos(theta), sin(theta) * sin(phi));
normal = ( * wi * (-1.0f)).normalize();
*pdf = (pdfs[0] * pdfs[1]) / (2.0f * M_PI * M_PI * sinf(theta));
if (sin(theta) == 0.0f) *pdf = 0.0f;
// TODO: fix - but not used
float c1, c2, c3;
c1 = img[(int)(fu * uDistrib->invCount) + (int)(fv * vDistribs[u]->invCount * nv)];
c2 = img[(int)(fu * uDistrib->invCount) + (int)(fv * vDistribs[u]->invCount * nv) + 1];
c3 = img[(int)(fu * uDistrib->invCount) + (int)(fv * vDistribs[u]->invCount * nv) + 2];
if (debug) {
int v = Clamp((int)fv, 0, nv - 1);
int index = v * nu + u;
img[3 * index] = 1.0f;
img[3 * index + 1] = 0.0f;
img[3 * index + 2] = 0.0f;
}
return vec3(c1, c2, c3);
}
float pdf(const vec3& point, const vec3& wi) {
const float theta = SphericalTheta(wi);
const float phi = SphericalPhi(wi);
float sintheta = sinf(theta);
if (sintheta == 0.0f) return 0.f;
const int u = Clamp((int)(phi * (1 / (2 * M_PI) * uDistrib->count)), 0, uDistrib->count - 1);
const int v = Clamp((int)(theta * (1 / M_PI) * vDistribs[u]->count), 0, vDistribs[u]->count - 1);
if (vDistribs[v]->funcInt * uDistrib->funcInt == 0.0f) return 0.0f;
return ((uDistrib->func[u] * vDistribs[u]->func[v]) /
(uDistrib->funcInt * vDistribs[u]->funcInt)) *
1.0f / (2.0f * M_PI * M_PI * sintheta);
}
void RGBToLuminanceImage(float* image, int nu, int nv, float* output)
{
for (int u = 0; u < nu; u++) {
for (int v = 0; v < nv; v++) {
int index = v * nu + u;
float r = img[index * 3] * 255;
float g = img[index * 3 + 1] * 255;
float b = img[index * 3 + 2] * 255;
float l = lumimance(r, g, b) / 256;
output[index] = l;
}
}
}
vec3 sampleMapFromDirection(const vec3& dir, const vec3& color) {
const float phi = SphericalPhi(dir.normalize());
const float theta = SphericalTheta(dir.normalize());
const int u = Clamp((int)(phi * (1 / (2 * M_PI) * uDistrib->count)), 0, uDistrib->count - 1);
const int v = Clamp((int)(theta * (1 / M_PI) * vDistribs[u]->count), 0, vDistribs[u]->count - 1);
const int index = v * nu + u;
const float r = img[index * 3];
const float g = img[index * 3 + 1];
const float b = img[index * 3 + 2];
if (debug) {
img[index * 3] = color.x;
img[index * 3 + 1] = color.y;
img[index * 3 + 2] = color.z;
}
return vec3(r, g, b);
}
void sampleRandomUniformDirection(vec3* wi, float* pdf) {
const double u1 = drandom();
const double u2 = drandom();
const float phi = 2.0f * M_PI * u1;
const float theta = acos(1.0f - 2.0f * u2);
*wi = vec3(sin(theta) * cos(phi), cos(theta), sin(theta) * sin(phi));
normal = *wi * (-1.0f);
*pdf = 1 / (4 * M_PI);
}
};
const int screenWidth = 600;
const int screenHeight = 600;
vec3 image[screenWidth * screenHeight]; // computed image
vec3 reference[screenWidth * screenHeight]; // reference image
// alpha of light source sampling, 0 .. BRDF only, 1.0 .. light only
double weight[screenWidth * screenHeight] = { 0 };
// Definition of the camera
class Camera
{
// center of projection and orthogonal basis of the camera
vec3 eye, lookat, right, up;
public:
void set(const vec3& _eye, const vec3& _lookat, const vec3& _vup, double fov)
{
eye = _eye;
lookat = _lookat;
vec3 w = eye - lookat;
double f = w.length();
right = cross(_vup, w).normalize() * f * tan(fov / 2);
up = cross(w, right).normalize() * f * tan(fov / 2);
}
Ray getRay(int X, int Y)
{ // X,Y - pixel coordinates, compute a primary ray
vec3 dir = lookat +
right * (2.0 * (X + 0.5) / screenWidth - 1) +
up * (2.0 * (Y + 0.5) / screenHeight - 1) - eye;
return Ray(eye, dir.normalize());
}
};
// Which sampling method should be used
enum Method { BRDF, BRDF_ENV, LIGHT_SOURCE, LIGHT_SOURCE_ENV, NAIVE , MIS, PATH_TRACING } method;
// The scene definition with main rendering method
class Scene
{
std::vector<Intersectable*> objects;
double totalPower;
int nLightSamples, nBRDFSamples;
public:
Camera camera;
InfiniteAreaLight envMap = InfiniteAreaLight("./EM/rotated/raw013.hdr");
void build()
{
// Create a simple scene
vec3 eyePos(0, 6, 18); // camera center
vec3 lightCenterPos(0, 4, -6); // first light source
bool PT_scene = true;
if (PT_scene) {
objects.push_back(new Rect(vec3(0, -2.5, 0), vec3(0,1,0), vec3(0,1,0), 7, 7, new GeneralMaterial(500, vec3(1, 1, 1), 1, 0)));
objects.push_back(new Sphere(vec3(-1.5, -1.5, 1), 1.2, new GeneralMaterial(500, vec3(1, 0, 0), 1, 0)));
objects.push_back(new Sphere(vec3(1.5, -1.5, 1), 1.2, new GeneralMaterial(500, vec3(0, 1, 0), 1, 0)));
objects.push_back(new Sphere(vec3(0, -1.5, -1), 1.2, new GeneralMaterial(500, vec3(0, 0, 1), 1, 0)));
objects.push_back(new Sphere(vec3(0, 1, 1), 1.2, new GeneralMaterial(500, vec3(1, 1, 0), 1, 0)));
for (auto& i : objects) {
i->power = 0;
}
} else {
// Create geometry - 4 rectangles
bool sameShininies = false;
if (sameShininies == true) {
objects.push_back(new Rect(vec3(0, -4, +2), eyePos, lightCenterPos, 4, 1, new TableMaterial(800)));
objects.push_back(new Rect(vec3(0, -3.5, -2), eyePos, lightCenterPos, 4, 1, new TableMaterial(800)));
objects.push_back(new Rect(vec3(0, -2.5, -6), eyePos, lightCenterPos, 4, 1, new TableMaterial(800)));
objects.push_back(new Rect(vec3(0, -1, -10), eyePos, lightCenterPos, 4, 1, new TableMaterial(800)));
}
else {
objects.push_back(new Rect(vec3(0, -4, +2), eyePos, lightCenterPos, 4, 1, new TableMaterial(500)));
objects.push_back(new Rect(vec3(0, -3.5, -2), eyePos, lightCenterPos, 4, 1, new TableMaterial(1000)));
objects.push_back(new Rect(vec3(0, -2.5, -6), eyePos, lightCenterPos, 4, 1, new TableMaterial(5000)));
objects.push_back(new Rect(vec3(0, -1, -10), eyePos, lightCenterPos, 4, 1, new TableMaterial(10000)));
}
// Create 4 light sources
objects.push_back(new Sphere(lightCenterPos + vec3(-4.5, 0, 0), 0.07, new LightMaterial(vec3(4, 2, 1))));
objects.push_back(new Sphere(lightCenterPos + vec3(-1.5, 0, 0), 0.16, new LightMaterial(vec3(2, 4, 1))));
objects.push_back(new Sphere(lightCenterPos + vec3(1.5, 0, 0), 0.4, new LightMaterial(vec3(2, 1, 4))));
objects.push_back(new Sphere(lightCenterPos + vec3(4.5, 0, 0), 1, new LightMaterial(vec3(4, 1, 2))));
}
// Set the camera
camera.set(eyePos, vec3(0, 0, 0), vec3(0, 1, 0), 35.0 * M_PI / 180.0);
totalPower = 0;
for (int i = 0; i < objects.size(); i++) {
totalPower += objects[i]->power;
}
}
// Set the weight for the sampling method
void setWeight(double wval)
{
for (int Y = 0; Y < screenHeight; Y++)
for (int X = 0; X < screenWidth; X++)
weight[Y * screenWidth + X] = wval;
}
// Render the scene
void render()
{
// Total number of samples per pixel is: nIterators*nTotalSamples
srand(1);
char buffer[100];
FILE* errorFile = 0;
switch (method) {
case BRDF:
nBRDFSamples = nTotalSamples;
nLightSamples = 0;
errorFile = fopen("BRDF.txt", "w");
setWeight(0.0);
break;
case PATH_TRACING:
case MIS:
nBRDFSamples = nTotalSamples / 2;
nLightSamples = nTotalSamples / 2;
errorFile = fopen("MIS.txt", "w");
setWeight(0.5);
break;
case NAIVE:
case LIGHT_SOURCE_ENV:
case LIGHT_SOURCE:
nBRDFSamples = 0;
nLightSamples = nTotalSamples;
errorFile = fopen("light.txt", "w");
setWeight(1.0);
break;
} // switch
double cost = 0;
bool debug = true;
// How many iterations
for (int iIter = 1; iIter <= nIterations; iIter++) {
double error = 0;
for (int Y = 0; Y < screenHeight; Y++) { // for all rows
#pragma omp parallel for schedule(dynamic)
for (int X = 0; X < screenWidth; X++) { // for all pixels in a row
//if (debug) { // debug particular pixel x,y, coordinates from pfsv (pfstools)
// X = 287;
// Y = 270;
//}
nLightSamples = (int)(weight[Y * screenWidth + X] * nTotalSamples + 0.5);
nBRDFSamples = nTotalSamples - nLightSamples;
cost += nBRDFSamples * costBRDF + nLightSamples * costLight;
// For a primary ray at pixel (X,Y) compute the color
vec3 color;
if (method == NAIVE) {
color = traceNaive(camera.getRay(X, Y));
} else if (method == MIS) {
color = traceMIS(camera.getRay(X, Y));
} else if (method == PATH_TRACING) {
color = pathTrace(camera.getRay(X, Y));
} else {
color = trace2(camera.getRay(X, Y));
}
double w = 1.0 / iIter; // the same weight for all samples for computing mean incrementally
image[Y * screenWidth + X] = color * w + image[Y * screenWidth + X] * (1.0 - w);
w = 1.0 / sqrt(iIter); // emphasize later samples
vec3 diff = reference[Y * screenWidth + X] - image[Y * screenWidth + X];
error += dot(diff, diff);
} // for X
} // for Y
double eff = 100000.0 * nIterations * nTotalSamples * screenWidth * screenHeight / error / cost;
printf("Iter: %d, Error: %4.2f, Efficiency: %f, Relative Efficiency: %f\n", iIter, sqrt(error), eff, eff / referenceEfficiency);
fprintf(errorFile, "%d, %f\n", iIter * nTotalSamples, sqrt(error));
} // for iTer
fclose(errorFile);
} // render
// Compute intersection between a ray and primitive
Hit firstIntersect(const Ray& ray, Intersectable* skip)
{
Hit bestHit;
for (int i = 0; i < objects.size(); i++) {
if (objects[i] == skip) continue;
if (method == LIGHT_SOURCE_ENV || method == BRDF_ENV || method == NAIVE) {
if (i >= 4 && i <= 7) {
continue;
}
}
Hit hit = objects[i]->intersect(ray); // hit.t < 0 if no intersection
if (hit.t > epsilon) {
if (bestHit.t < 0 || hit.t < bestHit.t) bestHit = hit;
}
}
return bestHit;
}
// Sample the light source from all the light sources in the scene
SphereLight* sampleLightSource(const vec3& illuminatedPoint) // the 3D point on an object
{
while (true) { // if no light source is selected due to floating point inaccuracies, repeat
double threshold = totalPower * drandom();
double running = 0;
for (int i = 0; i < objects.size(); i++) {
running += objects[i]->power; // select light source with the probability proportional to its power
if (running > threshold) {
Sphere* sphere = (Sphere*)objects[i];
vec3 point, normal;
// select a point on the visible half of the light source
((Sphere*)objects[i])->sampleUniformPoint(illuminatedPoint, point, normal);
return new SphereLight(sphere, point, normal);
} // if
} // for i
} // for ever
}
Light& sampleLight(vec3& point, vec3& direction) {
if (method == LIGHT_SOURCE || method == MIS) {
SphereLight* lightSample = sampleLightSource(point); // generate a light sample
vec3 outDir = lightSample->point - point; // compute direction towards sample
direction = outDir;
return *lightSample;
} else {
// return env map
float pdf;
envMap.sampleLight(point, &direction, &pdf);
return envMap;
}
}
vec3 trace2(const Ray& r)
{
// error measures for the two combined techniques: used for adaptation
Hit hit = firstIntersect(r, NULL); // find visible point
if (hit.t < 0) {
if (method == LIGHT_SOURCE_ENV) {
return envMap.sampleMapFromDirection(r.dir, vec3(0,1,0));
} else {
return vec3(0, 0, 0);
}
}
// The energy emanated from the material
vec3 radianceEmitted = hit.material->Le;
if (hit.material->diffuseAlbedo.average() < epsilon && hit.material->specularAlbedo.average() < epsilon) {
return radianceEmitted; // if albedo is low, no energy can be reefleted
}
// Compute the contribution of reflected lgiht
vec3 radianceBRDFSampling(0, 0, 0);
vec3 radianceLightSourceSampling(0, 0, 0);
vec3 inDir = r.dir * (-1); // incident direction
int nTotalSamples = (nLightSamples + nBRDFSamples);
double alpha = (double)nLightSamples / nTotalSamples;
// The direct illumination for chosen number of samples
for (int i = 0; i < nLightSamples; i++) {
vec3 outDir = vec3(0, 0, 0);
Light& lightSample = sampleLight(hit.position, outDir);