void PhotonShootingTask::Run() { // Declare local variables for _PhotonShootingTask_ MemoryArena arena; RNG rng(31 * taskNum); vector<Photon> localDirectPhotons, localIndirectPhotons, localCausticPhotons; vector<RadiancePhoton> localRadiancePhotons; uint32_t totalPaths = 0; bool causticDone = (integrator->nCausticPhotonsWanted == 0); bool indirectDone = (integrator->nIndirectPhotonsWanted == 0); PermutedHalton halton(6, rng); vector<Spectrum> localRpReflectances, localRpTransmittances; while (true) { // Follow photon paths for a block of samples const uint32_t blockSize = 4096; for (uint32_t i = 0; i < blockSize; ++i) { float u[6]; halton.Sample(++totalPaths, u); // Choose light to shoot photon from float lightPdf; int lightNum = lightDistribution->SampleDiscrete(u[0], &lightPdf); const Light *light = scene->lights[lightNum]; // Generate _photonRay_ from light source and initialize _alpha_ RayDifferential photonRay; float pdf; LightSample ls(u[1], u[2], u[3]); Normal Nl; Spectrum Le = light->Sample_L(scene, ls, u[4], u[5], time, &photonRay, &Nl, &pdf); if (pdf == 0.f || Le.IsBlack()) continue; Spectrum alpha = (AbsDot(Nl, photonRay.d) * Le) / (pdf * lightPdf); if (!alpha.IsBlack()) { // Follow photon path through scene and record intersections PBRT_PHOTON_MAP_STARTED_RAY_PATH(&photonRay, &alpha); bool specularPath = true; Intersection photonIsect; int nIntersections = 0; while (scene->Intersect(photonRay, &photonIsect)) { ++nIntersections; // Handle photon/surface intersection alpha *= renderer->Transmittance(scene, photonRay, NULL, rng, arena); BSDF *photonBSDF = photonIsect.GetBSDF(photonRay, arena); BxDFType specularType = BxDFType(BSDF_REFLECTION | BSDF_TRANSMISSION | BSDF_SPECULAR); bool hasNonSpecular = (photonBSDF->NumComponents() > photonBSDF->NumComponents(specularType)); Vector wo = -photonRay.d; if (hasNonSpecular) { // Deposit photon at surface Photon photon(photonIsect.dg.p, alpha, wo); bool depositedPhoton = false; if (specularPath && nIntersections > 1) { if (!causticDone) { PBRT_PHOTON_MAP_DEPOSITED_CAUSTIC_PHOTON(&photonIsect.dg, &alpha, &wo); depositedPhoton = true; localCausticPhotons.push_back(photon); } } else { // Deposit either direct or indirect photon // stop depositing direct photons once indirectDone is true; don't // want to waste memory storing too many if we're going a long time // trying to get enough caustic photons desposited. if (nIntersections == 1 && !indirectDone && integrator->finalGather) { PBRT_PHOTON_MAP_DEPOSITED_DIRECT_PHOTON(&photonIsect.dg, &alpha, &wo); depositedPhoton = true; localDirectPhotons.push_back(photon); } else if (nIntersections > 1 && !indirectDone) { PBRT_PHOTON_MAP_DEPOSITED_INDIRECT_PHOTON(&photonIsect.dg, &alpha, &wo); depositedPhoton = true; localIndirectPhotons.push_back(photon); } } // Possibly create radiance photon at photon intersection point if (depositedPhoton && integrator->finalGather && rng.RandomFloat() < .125f) { Normal n = photonIsect.dg.nn; n = Faceforward(n, -photonRay.d); localRadiancePhotons.push_back(RadiancePhoton(photonIsect.dg.p, n)); Spectrum rho_r = photonBSDF->rho(rng, BSDF_ALL_REFLECTION); localRpReflectances.push_back(rho_r); Spectrum rho_t = photonBSDF->rho(rng, BSDF_ALL_TRANSMISSION); localRpTransmittances.push_back(rho_t); } } if (nIntersections >= integrator->maxPhotonDepth) break; // Sample new photon ray direction Vector wi; float pdf; BxDFType flags; Spectrum fr = photonBSDF->Sample_f(wo, &wi, BSDFSample(rng), &pdf, BSDF_ALL, &flags); if (fr.IsBlack() || pdf == 0.f) break; Spectrum anew = alpha * fr * AbsDot(wi, photonBSDF->dgShading.nn) / pdf; // Possibly terminate photon path with Russian roulette float continueProb = min(1.f, anew.y() / alpha.y()); if (rng.RandomFloat() > continueProb) break; alpha = anew / continueProb; specularPath &= ((flags & BSDF_SPECULAR) != 0); if (indirectDone && !specularPath) break; photonRay = RayDifferential(photonIsect.dg.p, wi, photonRay, photonIsect.rayEpsilon); } PBRT_PHOTON_MAP_FINISHED_RAY_PATH(&photonRay, &alpha); } arena.FreeAll(); } // Merge local photon data with data in _PhotonIntegrator_ { MutexLock lock(mutex); // Give up if we're not storing enough photons if (abortTasks) return; if (nshot > 500000 && (unsuccessful(integrator->nCausticPhotonsWanted, causticPhotons.size(), blockSize) || unsuccessful(integrator->nIndirectPhotonsWanted, indirectPhotons.size(), blockSize))) { Error("Unable to store enough photons. Giving up.\n"); causticPhotons.erase(causticPhotons.begin(), causticPhotons.end()); indirectPhotons.erase(indirectPhotons.begin(), indirectPhotons.end()); radiancePhotons.erase(radiancePhotons.begin(), radiancePhotons.end()); abortTasks = true; return; } progress.Update(localIndirectPhotons.size() + localCausticPhotons.size()); nshot += blockSize; // Merge indirect photons into shared array if (!indirectDone) { integrator->nIndirectPaths += blockSize; for (uint32_t i = 0; i < localIndirectPhotons.size(); ++i) indirectPhotons.push_back(localIndirectPhotons[i]); localIndirectPhotons.erase(localIndirectPhotons.begin(), localIndirectPhotons.end()); if (indirectPhotons.size() >= integrator->nIndirectPhotonsWanted) indirectDone = true; nDirectPaths += blockSize; for (uint32_t i = 0; i < localDirectPhotons.size(); ++i) directPhotons.push_back(localDirectPhotons[i]); localDirectPhotons.erase(localDirectPhotons.begin(), localDirectPhotons.end()); } // Merge direct, caustic, and radiance photons into shared array if (!causticDone) { integrator->nCausticPaths += blockSize; for (uint32_t i = 0; i < localCausticPhotons.size(); ++i) causticPhotons.push_back(localCausticPhotons[i]); localCausticPhotons.erase(localCausticPhotons.begin(), localCausticPhotons.end()); if (causticPhotons.size() >= integrator->nCausticPhotonsWanted) causticDone = true; } for (uint32_t i = 0; i < localRadiancePhotons.size(); ++i) radiancePhotons.push_back(localRadiancePhotons[i]); localRadiancePhotons.erase(localRadiancePhotons.begin(), localRadiancePhotons.end()); for (uint32_t i = 0; i < localRpReflectances.size(); ++i) rpReflectances.push_back(localRpReflectances[i]); localRpReflectances.erase(localRpReflectances.begin(), localRpReflectances.end()); for (uint32_t i = 0; i < localRpTransmittances.size(); ++i) rpTransmittances.push_back(localRpTransmittances[i]); localRpTransmittances.erase(localRpTransmittances.begin(), localRpTransmittances.end()); } // Exit task if enough photons have been found if (indirectDone && causticDone) break; } }
void LightShootingTask::Run() { // tady by mel byt kod z photon mappingu MemoryArena arena; uint32_t totalPaths = 0; RNG rng(seed); PermutedHalton halton(6, rng); while (true) { // Follow photon paths for a block of samples const uint32_t blockSize = 4096; for (uint32_t i = 0; i < blockSize; ++i) { float u[6]; halton.Sample(++totalPaths, u); // Choose light to shoot photon from float lightPdf; int lightNum = lightDistribution->SampleDiscrete(u[0], &lightPdf); const Light *light = scene->lights[lightNum]; // Generate _photonRay_ from light source and initialize _alpha_ RayDifferential photonRay; float pdf; LightSample ls(u[1], u[2], u[3]); Normal Nl; Spectrum Le = light->Sample_L(scene, ls, u[4], u[5],time, &photonRay, &Nl, &pdf); if (pdf == 0.f || Le.IsBlack()) continue; Spectrum alpha = (AbsDot(Nl, photonRay.d) * Le) / (pdf * lightPdf); if (!alpha.IsBlack()) { // Follow photon path through scene and record intersections PBRT_PHOTON_MAP_STARTED_RAY_PATH(&photonRay, &alpha); bool specularPath = true; Intersection photonIsect; int nIntersections = 0; while (scene->Intersect(photonRay, &photonIsect)) { ++nIntersections; //MC tady by mel byt i kod pro volumetriku // Handle photon/surface intersection // alpha *= renderer->Transmittance(scene, photonRay, NULL, rng, arena); BSDF *photonBSDF = photonIsect.GetBSDF(photonRay, arena); Vector wo = -photonRay.d; //MC tady se ukladaly photony takze tady bych mel ukladat samples do filmu kamery // // Deposit photon at surface //Photon photon(photonIsect.dg.p, alpha, wo); //tuhle metodu chci pouzit //filmAddSample() if (nIntersections >= maxDepth) break; // Sample new photon ray direction Vector wi; float pdf; BxDFType flags; Spectrum fr = photonBSDF->Sample_f(wo, &wi, BSDFSample(rng), &pdf, BSDF_ALL, &flags); if (fr.IsBlack() || pdf == 0.f) break; Spectrum anew = alpha * fr * AbsDot(wi, photonBSDF->dgShading.nn) / pdf; // Possibly terminate photon path with Russian roulette float continueProb = min(1.f, anew.y() / alpha.y()); if (rng.RandomFloat() > continueProb) break; alpha = anew / continueProb; specularPath &= ((flags & BSDF_SPECULAR) != 0); photonRay = RayDifferential(photonIsect.dg.p, wi, photonRay, photonIsect.rayEpsilon); } PBRT_PHOTON_MAP_FINISHED_RAY_PATH(&photonRay, &alpha); } arena.FreeAll(); } //termination criteria ??? if (totalPaths==maxPathCount) { break; } } }