Color3f Li(const Scene *scene, Sampler *sampler, const Ray3f &ray) const {
/* Find the surface that is visible in the requested direction */
Intersection its;
//check if the ray intersects the scene
if (!scene->rayIntersect(ray, its)) {
//check if a distant disk light is set
const Emitter* distantsDisk = scene->getDistantEmitter();
if(distantsDisk == nullptr ) return Color3f(0.0f);
//sample the distant disk light
return distantsDisk->sampleL(ray.d);
}
//get the radiance of hitten object
Color3f Le(0.0f, 0.0f, 0.0f);
if (its.mesh->isEmitter() ) {
const Emitter* areaLightEM = its.mesh->getEmitter();
const areaLight* aEM = static_cast<const areaLight *> (areaLightEM);
Le = aEM->sampleL(-ray.d, its.shFrame.n, its);
}
//get the asigned BSDF
const BSDF* curBSDF = its.mesh->getBSDF();
Color3f Ld(0.0f, 0.0f, 0.0f);
Color3f f(0.0f, 0.0f, 0.0f);
Color3f totalLight(0.0f, 0.0f, 0.0f);
//transform to the local frame
//create a BRDF Query
BSDFQueryRecord query = BSDFQueryRecord(its.toLocal(-ray.d), Vector3f(0.0f), EMeasure::ESolidAngle);
//sample the BRDF
Color3f mats = curBSDF->sample(query, sampler->next2D());
if(mats.maxCoeff() > 0.0f) {
//Check for the light source
Vector3f wo = its.toWorld(query.wo);
Ray3f shadowRay(its.p, wo);
Intersection itsShadow;
if (scene->rayIntersect(shadowRay, itsShadow)) {
//intersection check if mesh is emitter
if(itsShadow.mesh->isEmitter()){
Ld = itsShadow.mesh->getEmitter()->radiance();
}
} else {
//check for distant disk light
const Emitter* distantsDisk = scene->getDistantEmitter();
if(distantsDisk != nullptr ) Ld = distantsDisk->sampleL(wo);
}
totalLight += Ld * mats;
}
return Le + totalLight;
}
Color3f Li(const Scene *scene, Sampler *sampler, const Ray3f &ray) const {
/* Find the surface that is visible in the requested direction */
Intersection its;
//check if the ray intersects the scene
if (!scene->rayIntersect(ray, its)) {
//check if a distant disk light is set
const Emitter* distantsDisk = scene->getDistantEmitter();
if(distantsDisk == nullptr ) return Color3f(0.0f);
//sample the distant disk light
Vector3f d = ray.d;
return distantsDisk->sampleL(d);
}
//get the Number of lights from the scene
const std::vector<Emitter *> lights = scene->getEmitters();
uint32_t nLights = lights.size();
Color3f tp(1.0f, 1.0f, 1.0f);
Color3f L(0.0f, 0.0f, 0.0f);
Ray3f pathRay(ray.o, ray.d);
bool deltaFlag = true;
while(true) {
if (its.mesh->isEmitter() && deltaFlag) {
const Emitter* areaLightEM = its.mesh->getEmitter();
const areaLight* aEM = static_cast<const areaLight *> (areaLightEM);
L += tp * aEM->sampleL(-pathRay.d, its.shFrame.n, its);
}
//Light sampling
//randomly select a lightsource
uint32_t var = uint32_t(std::min(sampler->next1D()*nLights, float(nLights) - 1.0f));
//init the light color
Color3f Li(0.0f, 0.0f, 0.0f);
Color3f Ld(1.0f, 1.0f, 1.0f);
//create a sample for the light
const BSDF* curBSDF = its.mesh->getBSDF();
const Point2f lightSample = sampler->next2D();
VisibilityTester vis;
Vector3f wo;
float lightpdf;
float bsdfpdf;
Normal3f n = its.shFrame.n;
deltaFlag = curBSDF->isDeltaBSDF();
//sample the light
{
Li = lights[var]->sampleL(its.p, Epsilon, lightSample , &wo, &lightpdf, &vis);
lightpdf /= float(nLights);
//check if the pdf of the sample is greater than 0 and if the color is not black
if(lightpdf > 0 && Li.maxCoeff() != 0.0f) {
//calculate the cosine term wi in my case the vector to the light
float cosTerm = std::abs(n.dot(wo));
const BSDFQueryRecord queryEM = BSDFQueryRecord(its.toLocal(- pathRay.d), its.toLocal(wo), EMeasure::ESolidAngle, sampler);
Color3f f = curBSDF->eval(queryEM);
if(f.maxCoeff() > 0.0f && f.minCoeff() >= 0.0f && vis.Unoccluded(scene)) {
bsdfpdf = curBSDF->pdf(queryEM);
float weight = BalanceHeuristic(float(1), lightpdf, float(1), bsdfpdf);
if(curBSDF->isDeltaBSDF()) weight = 1.0f;
if(bsdfpdf > 0.0f) {
Ld = (weight * f * Li * cosTerm) / lightpdf;
L += tp * Ld;
} else {
//cout << "bsdfpdf = " << bsdfpdf << endl;
//cout << "f = " << f << endl;
}
}
}
}
//Material part
BSDFQueryRecord queryMats = BSDFQueryRecord(its.toLocal(-pathRay.d), Vector3f(0.0f), EMeasure::ESolidAngle, sampler);
Color3f fi = curBSDF->sample(queryMats, sampler->next2D());
bsdfpdf = curBSDF->pdf(queryMats);
lightpdf = 0.0f;
if(fi.maxCoeff() > 0.0f && fi.minCoeff() >= 0.0f) {
if(bsdfpdf > 0.0f) {
Ray3f shadowRay(its.p, its.toWorld(queryMats.wo));
Intersection lightIsect;
if (scene->rayIntersect(shadowRay, lightIsect)) {
if(lightIsect.mesh->isEmitter()){
const Emitter* areaLightEMcur = lightIsect.mesh->getEmitter();
const areaLight* aEMcur = static_cast<const areaLight *> (areaLightEMcur);
Li = aEMcur->sampleL(-shadowRay.d, lightIsect.shFrame.n, lightIsect);
lightpdf = aEMcur->pdf(its.p, (lightIsect.p - its.p).normalized(), lightIsect.p, Normal3f(lightIsect.shFrame.n));
}
} else {
const Emitter* distantsDisk = scene->getDistantEmitter();
if(distantsDisk != nullptr ) {
//check if THIS is right!
Li = distantsDisk->sampleL(lightIsect.toWorld(queryMats.wo));
lightpdf = distantsDisk->pdf(Point3f(0.0f), wo, Point3f(0.0f), Normal3f(0.0f));
}
}
lightpdf /= float(nLights);
//calculate the weights
float weight = BalanceHeuristic(float(1), bsdfpdf, float(1), lightpdf);
//check if the lightcolor is not black
if(Li.maxCoeff() > 0.0f && lightpdf > 0.0f ) {
//wo in my case the vector to the light
Ld = weight * Li * fi;
L += tp * Ld;
}
}
tp *= fi;
} else {
break;
}
wo = its.toWorld(queryMats.wo);
pathRay = Ray3f(its.p, wo);
if (!scene->rayIntersect(pathRay, its)) {
const Emitter* distantsDisk = scene->getDistantEmitter();
if(distantsDisk != nullptr ) {
//sample the distant disk light
Vector3f d = pathRay.d;
L += tp * distantsDisk->sampleL(d);
}
break;
}
float maxCoeff = tp.maxCoeff();
float q = std::min(0.99f, maxCoeff);
if(q < sampler->next1D()){
break;
}
tp /= q;
}
return L;
}
void preprocess(const Scene *scene) {
/* Create a sample generator for the preprocess step */
Sampler *sampler = static_cast<Sampler *>(
NoriObjectFactory::createInstance("independent", PropertyList()));
Emitter* distantsDisk = scene->getDistantEmitter();
if(distantsDisk != nullptr ) {
float lngstDir = scene->getBoundingBox().getLongestDirection();
distantsDisk->setMaxRadius(lngstDir);
}
/* Allocate memory for the photon map */
m_photonMap = std::unique_ptr<PhotonMap>(new PhotonMap());
m_photonMap->reserve(m_photonCount);
/* Estimate a default photon radius */
if (m_photonRadius == 0)
m_photonRadius = scene->getBoundingBox().getExtents().norm() / 500.0f;
int storedPhotons = 0;
const std::vector<Emitter *> lights = scene->getEmitters();
int nLights = lights.size();
Color3f tp(1.0f, 1.0f, 1.0f);
cout << "Starting to create "<< m_photonCount << " photons!" << endl;
int percentDone= 0;
int onePercent = int(floor(m_photonCount / 100.0));
// create the expected number of photons
while(storedPhotons < m_photonCount) {
//uniformly sample 1 light (assuming that we only have area lights)
int var = int(std::min(sampler->next1D()*nLights, float(nLights) - 1.0f));
const areaLight* curLight = static_cast<const areaLight *> (lights[var]);
//sample a photon
Photon curPhoton;
Vector3f unQuantDir(0.0f,0.0f,0.0f);
curLight->samplePhoton(sampler, curPhoton, 1, nLights, unQuantDir);
Color3f alpha = curPhoton.getPower();
Color3f tp(1.0f, 1.0f, 1.0f);
//trace the photon
Intersection its;
Ray3f photonRay(curPhoton.getPosition(), unQuantDir);
m_shootedRays++;
if (scene->rayIntersect(photonRay, its)) {
while(true) {
const BSDF* curBSDF = its.mesh->getBSDF();
if (curBSDF->isDiffuse()) {
//store the photon
m_photonMap->push_back(Photon(
its.p /* Position */,
-photonRay.d /* Direction*/,
tp * alpha /* Power */
));
storedPhotons++;
}
if(!(storedPhotons < m_photonCount)) break;
BSDFQueryRecord query = BSDFQueryRecord(its.toLocal(-photonRay.d), Vector3f(0.0f), EMeasure::ESolidAngle);
Color3f fi = curBSDF->sample(query, sampler->next2D());
if(fi.maxCoeff() == 0.0f) break;
tp *= fi;
Vector3f wo = its.toWorld(query.wo);
photonRay = Ray3f(its.p, wo);
//ray escapes the scene
if (!scene->rayIntersect(photonRay, its)) break;
//stop critirium russian roulette
float q = tp.maxCoeff();
if(q < sampler->next1D()) break;
tp /= q;
}
}
if(onePercent != 0) {
if(storedPhotons % onePercent == 0){
int percent = int(floor(storedPhotons / onePercent));
if(percent % 10 == 0 && percentDone != percent){
percentDone = percent;
cout << percent << "%" << endl;
}
}
}
}
/* Build the photon map */
m_photonMap->build();
}
Color3f Li(const Scene *scene, Sampler *sampler, const Ray3f &ray) const {
/* Find the surface that is visible in the requested direction */
Intersection its;
//check if the ray intersects the scene
if (!scene->rayIntersect(ray, its)) {
return Color3f(0.0f);
}
Color3f tp(1.0f, 1.0f, 1.0f);
Color3f L(0.0f, 0.0f, 0.0f);
Ray3f pathRay(ray.o, ray.d);
while(true) {
//get the radiance of hitten object
if (its.mesh->isEmitter() ) {
const Emitter* areaLightEM = its.mesh->getEmitter();
const areaLight* aEM = static_cast<const areaLight *> (areaLightEM);
L += tp * aEM->sampleL(-pathRay.d, its.shFrame.n, its);
}
//get the asigned BSDF
const BSDF* curBSDF = its.mesh->getBSDF();
//transform to the local frame
BSDFQueryRecord query = BSDFQueryRecord(its.toLocal(-pathRay.d), Vector3f(0.0f), EMeasure::ESolidAngle);
//Normal3f n = its.shFrame.n;
if(curBSDF->isDiffuse()) {
std::vector<uint32_t> results;
m_photonMap->search(its.p, m_photonRadius, results);
Color3f Li(0.0f, 0.0f, 0.0f);
int k = results.size();
//cout << k << endl;
if(k > 0) {
//cout << results.size() << " Photons found!" << endl;
//get the power from all photons
//for (uint32_t i : results)
//const Photon &photonk = (*m_photonMap)[k-1];
Color3f Lindir(0.0f, 0.0f, 0.0f);
for (int i = 0; i < k; ++i)
{
const Photon &photon = (*m_photonMap)[results[i]];
Vector3f wi = its.toLocal(photon.getDirection());
Vector3f wo = its.toLocal(its.shFrame.n);
BSDFQueryRecord dummy = BSDFQueryRecord(wi, wo, EMeasure::ESolidAngle);
Color3f f = curBSDF->eval(dummy);
Lindir += (tp * f) * photon.getPower() / (M_PI * m_photonRadius * m_photonRadius);
}
Li += Lindir;
//cout << "Li = " << Li.toString() << endl;
if(Li.maxCoeff() > 0.0f)
L += Li / m_shootedRays;
}
break;
}
//sample the BRDF
Color3f fi = curBSDF->sample(query, sampler->next2D());
//check for black brdf
if(fi.maxCoeff() > 0.0f) {
tp *= fi;
} else {
//stop
// hit a black brdf
break;
}
Vector3f wo = its.toWorld(query.wo);
pathRay = Ray3f(its.p, wo);
//ray escapes the scene
if (!scene->rayIntersect(pathRay, its)) break;
//stop critirium russian roulette
float maxCoeff = tp.maxCoeff();
float q = std::min(0.99f, maxCoeff);
if(q < sampler->next1D()) break;
tp /= q;
}
return L;
}
