void SamplerRenderer::Render(const Scene *scene) {
PBRT_FINISHED_PARSING();
// Allow integrators to do pre-processing for the scene
PBRT_STARTED_PREPROCESSING();
surfaceIntegrator->Preprocess(scene, camera, this);
volumeIntegrator->Preprocess(scene, camera, this);
PBRT_FINISHED_PREPROCESSING();
PBRT_STARTED_RENDERING();
// Allocate and initialize _sample_
Sample *sample = new Sample(sampler, surfaceIntegrator,
volumeIntegrator, scene);
// Create and launch _SamplerRendererTask_s for rendering image
// Compute number of _SamplerRendererTask_s to create for rendering
int nPixels = camera->film->xResolution * camera->film->yResolution;
int nTasks = max(32 * NumSystemCores(), nPixels / (16*16));
nTasks = RoundUpPow2(nTasks);
ProgressReporter reporter(nTasks, "Rendering");
vector<Task *> renderTasks;
for (int i = 0; i < nTasks; ++i)
renderTasks.push_back(new SamplerRendererTask(scene, this, camera, sampler,
reporter,
sample, nTasks-1-i, nTasks));
EnqueueTasks(renderTasks);
WaitForAllTasks();
for (uint32_t i = 0; i < renderTasks.size(); ++i)
delete renderTasks[i];
reporter.Done();
PBRT_FINISHED_RENDERING();
// Clean up after rendering and store final image
delete sample;
camera->film->WriteImage();
}
void IrradianceCacheIntegrator::Preprocess(const Scene *scene,
const Camera *camera, const Renderer *renderer) {
BBox wb = scene->WorldBound();
Vector delta = .01f * (wb.pMax - wb.pMin);
wb.pMin -= delta;
wb.pMax += delta;
octree = new Octree<IrradianceSample *>(wb);
// Prime irradiance cache
minWeight *= 1.5f;
int xstart, xend, ystart, yend;
camera->film->GetSampleExtent(&xstart, &xend, &ystart, ¥d);
HaltonSampler sampler(xstart, xend, ystart, yend, 1,
camera->shutterOpen, camera->shutterClose);
Sample *sample = new Sample(&sampler, this, NULL, scene);
const int nTasks = 64;
ProgressReporter progress(nTasks, "Priming irradiance cache");
vector<Task *> tasks;
for (int i = 0; i < nTasks; ++i)
tasks.push_back(new IrradiancePrimeTask(scene, renderer, camera,
&sampler, sample, this,
progress, i, nTasks));
EnqueueTasks(tasks);
WaitForAllTasks();
for (uint32_t i = 0; i < tasks.size(); ++i)
delete tasks[i];
progress.Done();
delete sample;
minWeight /= 1.5f;
}
void SurfacePointsRenderer::Render(const Scene &scene) {
// Declare shared variables for Poisson point generation
BBox octBounds = scene.WorldBound();
octBounds.Expand(.001f * powf(octBounds.Volume(), 1.f/3.f));
Octree<SurfacePoint> pointOctree(octBounds);
// Create scene bounding sphere to catch rays that leave the scene
Point sceneCenter;
float sceneRadius;
scene.WorldBound().BoundingSphere(&sceneCenter, &sceneRadius);
Transform ObjectToWorld(Translate(sceneCenter - Point(0,0,0)));
Transform WorldToObject(Inverse(ObjectToWorld));
Reference<Shape> sph = new Sphere(&ObjectToWorld, &WorldToObject,
true, sceneRadius, -sceneRadius, sceneRadius, 360.f);
//Reference<Material> nullMaterial = Reference<Material>(NULL);
Material nullMaterial;
GeometricPrimitive sphere(sph, nullMaterial, NULL);
int maxFails = 2000, repeatedFails = 0, maxRepeatedFails = 0;
if (PbrtOptions.quickRender) maxFails = max(10, maxFails / 10);
int totalPathsTraced = 0, totalRaysTraced = 0, numPointsAdded = 0;
ProgressReporter prog(maxFails, "Depositing samples");
// Launch tasks to trace rays to find Poisson points
PBRT_SUBSURFACE_STARTED_RAYS_FOR_POINTS();
vector<Task *> tasks;
RWMutex *mutex = RWMutex::Create();
int nTasks = NumSystemCores();
for (int i = 0; i < nTasks; ++i)
tasks.push_back(new SurfacePointTask(scene, pCamera, time, i,
minDist, maxFails, *mutex, repeatedFails, maxRepeatedFails,
totalPathsTraced, totalRaysTraced, numPointsAdded, sphere, pointOctree,
points, prog));
EnqueueTasks(tasks);
WaitForAllTasks();
for (uint32_t i = 0; i < tasks.size(); ++i)
delete tasks[i];
RWMutex::Destroy(mutex);
prog.Done();
PBRT_SUBSURFACE_FINISHED_RAYS_FOR_POINTS(totalRaysTraced, numPointsAdded);
if (filename != "") {
// Write surface points to file
FILE *f = fopen(filename.c_str(), "w");
if (!f) {
Error("Unable to open output file \"%s\" (%s)", filename.c_str(),
strerror(errno));
return;
}
fprintf(f, "# points generated by SurfacePointsRenderer\n");
fprintf(f, "# position (x,y,z), normal (x,y,z), area, rayEpsilon\n");
for (u_int i = 0; i < points.size(); ++i) {
const SurfacePoint &sp = points[i];
fprintf(f, "%g %g %g %g %g %g %g %g\n", sp.p.x, sp.p.y, sp.p.z,
sp.n.x, sp.n.y, sp.n.z, sp.area, sp.rayEpsilon);
}
fclose(f);
}
}
void LightTracerRenderer::Render(const Scene *scene) {
// Compute light power CDF for photon shooting
Distribution1D *lightDistribution = ComputeLightSamplingCDF(scene);
vector<Task *> lightShootingTasks;
int nTasks = NumSystemCores();
//iteratively increase fidelity of the image
for (int iter=0; iter<niter; iter++) {
//multi tasking one for each processor
for (int i = 0; i < nTasks; ++i)
lightShootingTasks.push_back(new LightShootingTask(scene,camera,lightDistribution, camera ? camera->shutterOpen : 0.f,maxPathCount,seed*(i+1)));
EnqueueTasks(lightShootingTasks);
WaitForAllTasks();
for (uint32_t i = 0; i < lightShootingTasks.size(); ++i)
delete lightShootingTasks[i];
//write image
camera->film->WriteImage();
}
}
void PhotonIntegrator::Preprocess(const Scene *scene,
const Camera *camera, const Renderer *renderer) {
if (scene->lights.size() == 0) return;
// Declare shared variables for photon shooting
Mutex *mutex = Mutex::Create();
int nDirectPaths = 0;
vector<Photon> causticPhotons, directPhotons, indirectPhotons;
vector<RadiancePhoton> radiancePhotons;
bool abortTasks = false;
causticPhotons.reserve(nCausticPhotonsWanted);
indirectPhotons.reserve(nIndirectPhotonsWanted);
uint32_t nshot = 0;
vector<Spectrum> rpReflectances, rpTransmittances;
// Compute light power CDF for photon shooting
Distribution1D *lightDistribution = ComputeLightSamplingCDF(scene);
// Run parallel tasks for photon shooting
ProgressReporter progress(nCausticPhotonsWanted+nIndirectPhotonsWanted, "Shooting photons");
vector<Task *> photonShootingTasks;
int nTasks = NumSystemCores();
for (int i = 0; i < nTasks; ++i)
photonShootingTasks.push_back(new PhotonShootingTask(
i, camera ? camera->shutterOpen : 0.f, *mutex, this, progress, abortTasks, nDirectPaths,
directPhotons, indirectPhotons, causticPhotons, radiancePhotons,
rpReflectances, rpTransmittances,
nshot, lightDistribution, scene, renderer));
EnqueueTasks(photonShootingTasks);
WaitForAllTasks();
for (uint32_t i = 0; i < photonShootingTasks.size(); ++i)
delete photonShootingTasks[i];
Mutex::Destroy(mutex);
progress.Done();
// Build kd-trees for indirect and caustic photons
KdTree<Photon> *directMap = NULL;
if (directPhotons.size() > 0)
directMap = new KdTree<Photon>(directPhotons);
if (causticPhotons.size() > 0)
causticMap = new KdTree<Photon>(causticPhotons);
if (indirectPhotons.size() > 0)
indirectMap = new KdTree<Photon>(indirectPhotons);
// Precompute radiance at a subset of the photons
if (finalGather && radiancePhotons.size()) {
// Launch tasks to compute photon radiances
vector<Task *> radianceTasks;
uint32_t numTasks = 64;
ProgressReporter progRadiance(numTasks, "Computing photon radiances");
for (uint32_t i = 0; i < numTasks; ++i)
radianceTasks.push_back(new ComputeRadianceTask(progRadiance,
i, numTasks, radiancePhotons, rpReflectances, rpTransmittances,
nLookup, maxDistSquared, nDirectPaths, directMap,
nIndirectPaths, indirectMap,
nCausticPaths, causticMap));
EnqueueTasks(radianceTasks);
WaitForAllTasks();
for (uint32_t i = 0; i < radianceTasks.size(); ++i)
delete radianceTasks[i];
progRadiance.Done();
radianceMap = new KdTree<RadiancePhoton>(radiancePhotons);
}
delete directMap;
}
void CreateRadianceProbes::Render(const Scene *scene) {
// Compute scene bounds and initialize probe integrators
if (bbox.pMin.x > bbox.pMax.x)
bbox = scene->WorldBound();
surfaceIntegrator->Preprocess(scene, camera, this);
volumeIntegrator->Preprocess(scene, camera, this);
Sample *origSample = new Sample(NULL, surfaceIntegrator, volumeIntegrator,
scene);
// Compute sampling rate in each dimension
Vector delta = bbox.pMax - bbox.pMin;
int nProbes[3];
for (int i = 0; i < 3; ++i)
nProbes[i] = max(1, Ceil2Int(delta[i] / probeSpacing));
// Allocate SH coefficient vector pointers for sample points
int count = nProbes[0] * nProbes[1] * nProbes[2];
Spectrum **c_in = new Spectrum *[count];
for (int i = 0; i < count; ++i)
c_in[i] = new Spectrum[SHTerms(lmax)];
// Compute random points on surfaces of scene
// Create scene bounding sphere to catch rays that leave the scene
Point sceneCenter;
float sceneRadius;
scene->WorldBound().BoundingSphere(&sceneCenter, &sceneRadius);
Transform ObjectToWorld(Translate(sceneCenter - Point(0,0,0)));
Transform WorldToObject(Inverse(ObjectToWorld));
Reference<Shape> sph = new Sphere(&ObjectToWorld, &WorldToObject,
true, sceneRadius, -sceneRadius, sceneRadius, 360.f);
Reference<Material> nullMaterial = Reference<Material>(NULL);
GeometricPrimitive sphere(sph, nullMaterial, NULL);
vector<Point> surfacePoints;
uint32_t nPoints = 32768, maxDepth = 32;
surfacePoints.reserve(nPoints + maxDepth);
Point pCamera = camera->CameraToWorld(camera->shutterOpen,
Point(0, 0, 0));
surfacePoints.push_back(pCamera);
RNG rng;
while (surfacePoints.size() < nPoints) {
// Generate random path from camera and deposit surface points
Point pray = pCamera;
Vector dir = UniformSampleSphere(rng.RandomFloat(), rng.RandomFloat());
float rayEpsilon = 0.f;
for (uint32_t i = 0; i < maxDepth; ++i) {
Ray ray(pray, dir, rayEpsilon, INFINITY, time);
Intersection isect;
if (!scene->Intersect(ray, &isect) &&
!sphere.Intersect(ray, &isect))
break;
surfacePoints.push_back(ray(ray.maxt));
DifferentialGeometry &hitGeometry = isect.dg;
pray = isect.dg.p;
rayEpsilon = isect.rayEpsilon;
hitGeometry.nn = Faceforward(hitGeometry.nn, -ray.d);
dir = UniformSampleSphere(rng.RandomFloat(), rng.RandomFloat());
dir = Faceforward(dir, hitGeometry.nn);
}
}
// Launch tasks to compute radiance probes at sample points
vector<Task *> tasks;
ProgressReporter prog(count, "Radiance Probes");
for (int i = 0; i < count; ++i)
tasks.push_back(new CreateRadProbeTask(i, nProbes, time,
bbox, lmax, includeDirectInProbes,
includeIndirectInProbes, nIndirSamples,
prog, origSample, surfacePoints,
scene, this, c_in[i]));
EnqueueTasks(tasks);
WaitForAllTasks();
for (uint32_t i = 0; i < tasks.size(); ++i)
delete tasks[i];
prog.Done();
// Write radiance probe coefficients to file
FILE *f = fopen(filename.c_str(), "w");
if (f) {
if (fprintf(f, "%d %d %d\n", lmax, includeDirectInProbes?1:0, includeIndirectInProbes?1:0) < 0 ||
fprintf(f, "%d %d %d\n", nProbes[0], nProbes[1], nProbes[2]) < 0 ||
fprintf(f, "%f %f %f %f %f %f\n", bbox.pMin.x, bbox.pMin.y, bbox.pMin.z,
bbox.pMax.x, bbox.pMax.y, bbox.pMax.z) < 0) {
Error("Error writing radiance file \"%s\" (%s)", filename.c_str(),
strerror(errno));
exit(1);
}
for (int i = 0; i < nProbes[0] * nProbes[1] * nProbes[2]; ++i) {
for (int j = 0; j < SHTerms(lmax); ++j) {
fprintf(f, " ");
if (c_in[i][j].Write(f) == false) {
Error("Error writing radiance file \"%s\" (%s)", filename.c_str(),
strerror(errno));
exit(1);
}
fprintf(f, "\n");
}
fprintf(f, "\n");
}
fclose(f);
}
for (int i = 0; i < nProbes[0] * nProbes[1] * nProbes[2]; ++i)
delete[] c_in[i];
delete[] c_in;
delete origSample;
}
void MetropolisRenderer::Render(const Scene *scene) {
PBRT_MLT_STARTED_RENDERING();
if (scene->lights.size() > 0) {
int x0, x1, y0, y1;
camera->film->GetPixelExtent(&x0, &x1, &y0, &y1);
float t0 = camera->shutterOpen, t1 = camera->shutterClose;
Distribution1D *lightDistribution = ComputeLightSamplingCDF(scene);
if (directLighting != NULL) {
PBRT_MLT_STARTED_DIRECTLIGHTING();
// Compute direct lighting before Metropolis light transport
if (nDirectPixelSamples > 0) {
LDSampler sampler(x0, x1, y0, y1, nDirectPixelSamples, t0, t1);
Sample *sample = new Sample(&sampler, directLighting, NULL, scene);
vector<Task *> directTasks;
int nDirectTasks = max(32 * NumSystemCores(),
(camera->film->xResolution * camera->film->yResolution) / (16*16));
nDirectTasks = RoundUpPow2(nDirectTasks);
ProgressReporter directProgress(nDirectTasks, "Direct Lighting");
for (int i = 0; i < nDirectTasks; ++i)
directTasks.push_back(new SamplerRendererTask(scene, this, camera, directProgress,
&sampler, sample, false, i, nDirectTasks));
std::reverse(directTasks.begin(), directTasks.end());
EnqueueTasks(directTasks);
WaitForAllTasks();
for (uint32_t i = 0; i < directTasks.size(); ++i)
delete directTasks[i];
delete sample;
directProgress.Done();
}
camera->film->WriteImage();
PBRT_MLT_FINISHED_DIRECTLIGHTING();
}
// Take initial set of samples to compute $b$
PBRT_MLT_STARTED_BOOTSTRAPPING(nBootstrap);
RNG rng(0);
MemoryArena arena;
vector<float> bootstrapI;
vector<PathVertex> cameraPath(maxDepth, PathVertex());
vector<PathVertex> lightPath(maxDepth, PathVertex());
float sumI = 0.f;
bootstrapI.reserve(nBootstrap);
MLTSample sample(maxDepth);
for (uint32_t i = 0; i < nBootstrap; ++i) {
// Generate random sample and path radiance for MLT bootstrapping
float x = Lerp(rng.RandomFloat(), x0, x1);
float y = Lerp(rng.RandomFloat(), y0, y1);
LargeStep(rng, &sample, maxDepth, x, y, t0, t1, bidirectional);
Spectrum L = PathL(sample, scene, arena, camera, lightDistribution,
&cameraPath[0], &lightPath[0], rng);
// Compute contribution for random sample for MLT bootstrapping
float I = ::I(L);
sumI += I;
bootstrapI.push_back(I);
arena.FreeAll();
}
float b = sumI / nBootstrap;
PBRT_MLT_FINISHED_BOOTSTRAPPING(b);
Info("MLT computed b = %f", b);
// Select initial sample from bootstrap samples
float contribOffset = rng.RandomFloat() * sumI;
rng.Seed(0);
sumI = 0.f;
MLTSample initialSample(maxDepth);
for (uint32_t i = 0; i < nBootstrap; ++i) {
float x = Lerp(rng.RandomFloat(), x0, x1);
float y = Lerp(rng.RandomFloat(), y0, y1);
LargeStep(rng, &initialSample, maxDepth, x, y, t0, t1,
bidirectional);
sumI += bootstrapI[i];
if (sumI > contribOffset)
break;
}
// Launch tasks to generate Metropolis samples
uint32_t nTasks = largeStepsPerPixel;
uint32_t largeStepRate = nPixelSamples / largeStepsPerPixel;
Info("MLT running %d tasks, large step rate %d", nTasks, largeStepRate);
ProgressReporter progress(nTasks * largeStepRate, "Metropolis");
vector<Task *> tasks;
Mutex *filmMutex = Mutex::Create();
Assert(IsPowerOf2(nTasks));
uint32_t scramble[2] = { rng.RandomUInt(), rng.RandomUInt() };
uint32_t pfreq = (x1-x0) * (y1-y0);
for (uint32_t i = 0; i < nTasks; ++i) {
float d[2];
Sample02(i, scramble, d);
tasks.push_back(new MLTTask(progress, pfreq, i,
d[0], d[1], x0, x1, y0, y1, t0, t1, b, initialSample,
scene, camera, this, filmMutex, lightDistribution));
}
EnqueueTasks(tasks);
WaitForAllTasks();
for (uint32_t i = 0; i < tasks.size(); ++i)
delete tasks[i];
progress.Done();
Mutex::Destroy(filmMutex);
delete lightDistribution;
}
camera->film->WriteImage();
PBRT_MLT_FINISHED_RENDERING();
}
int main(int argc, char *argv[]) {
if (argc != 2) {
fprintf(stderr, "usage: mbrast [grid_file.out]\n");
return 1;
}
// Read grids from grid dump file
std::vector<ShadedGrid> grids;
if (!ReadGrids(argv[1], &grids))
return 1;
InitSamples();
// Extract the name of the scene in case a full pathname was provided
// on the command line
char *sceneName = rindex(argv[1], '/');
if (sceneName != NULL)
++sceneName;
else
sceneName = argv[1];
// Remove trailing ".grids" from scene name
char *end = rindex(sceneName, '.');
assert(end);
*end = '\0';
printf("Rendering scene \"%s\"\n", sceneName);
// Change this call to switch to creating an instance of your 3D
// rasterizer once you start implementing it.
#if MBRAST_MODE == NAIVE_RAST_2D || MBRAST_MODE == SMART_RAST_2D
Rasterizer *rast = Create2DRasterizer();
#elif MBRAST_MODE == BASIC_RAST_3D || MBRAST_MODE == INTER_RAST_3D
Rasterizer *rast = Create3DRasterizer();
#elif MBRAST_MODE == BASIC_RAST_5D
Rasterizer *rast = Create5DRasterizer();
#endif
// Initialize task system for multithreading if the rasterizer
// indicates that it's thread safe.
bool useTasks = rast->IsThreadSafe();
int nThreads = NumSystemCores();
assert(nThreads < MAX_CORES);
if (useTasks) {
printf("Using %d threads!\n", nThreads);
TasksInit();
}
// Render the scene multiple times, with each of the pixelSamples
// sample counts. The sample counts must all be powers of two.
// The bucketSize array, which must be the same size as
// pixelSamples[], gives the length of the side of the bucket we'll
// decompose the image into for the corresponding sample count.
int pixelSamples[] = { 1, 4, 32 };
int bucketSize[] = { 64, 32, 8 };
assert(sizeof(pixelSamples) == sizeof(bucketSize));
int samplesSize = sizeof(pixelSamples) / sizeof(pixelSamples[0]);
int failures = 0;
for (int samplesIndex = 0; samplesIndex < samplesSize; ++samplesIndex) {
assert(pixelSamples[samplesIndex] <= MAX_SAMPLES_PER_PIXEL);
int nPixelSamples = pixelSamples[samplesIndex];
int bucketExtent = bucketSize[samplesIndex];
printf("Rendering with %d samples per pixel\n", nPixelSamples);
// 720p resolution. (This can't be easily changed, as it's baked
// into the xy coordinates of the micropolygons. So changing this
// here would require a corresponding adjustment to those
// coordinate values when the grids are read in....)
int xRes = 1280, yRes = 720;
// Allow the rasterizer to preprocess the grids
ResetAndStartTimer();
rast->PreprocessGrids(grids, bucketExtent, xRes, yRes);
double preprocessCycles = GetElapsedMCycles() / 1024.;
printf(" Spent %.3f billion cycles on grid preprocessing.\n",
preprocessCycles);
// Allocate final output image as well as one Bucket structure for
// each rasterization task thread we're running; this way the
// rasterizer can update the framebuffer in its Bucket directly
// without needing to coordinate with any other rasterizer threads.
uint8_t *image = new uint8_t[xRes * yRes * 3];
Bucket *buckets[MAX_CORES];
int nBuckets = useTasks ? nThreads : 1;
for (int i = 0; i < nBuckets; ++i)
buckets[i] = new Bucket(bucketExtent, nPixelSamples);
// Render with intervals set from 1 to the number of pixel samples
// in multiples of two.
for (int logIntervals = 0; (1 << logIntervals) <= nPixelSamples;
++logIntervals) {
int nIntervals = (1 << logIntervals);
printf(" Rendering with %d intervals: ", nIntervals);
fflush(stdout);
if (useTasks) {
// Create a RastTask instance for each of the buckets of
// the image; do this outside of the timer so as not to
// penalize for the unnecessary dynamic allocation overhead
// in the implementation here.
std::vector<Task *> rastTasks;
for (int y = 0; y < yRes; y += bucketExtent) {
for (int x = 0; x < xRes; x += bucketExtent) {
int x1 = std::min(x + bucketExtent, xRes);
int y1 = std::min(y + bucketExtent, yRes);
RastTask *rt = new RastTask(rast, &buckets[0], x, y,
x1, y1, nIntervals, grids,
image, xRes, yRes);
rastTasks.push_back(rt);
}
}
ResetAndStartTimer();
EnqueueTasks(rastTasks);
WaitForAllTasks();
}
else {
// If not using tasks, just loop over all of the buckets
// and rasterize.
ResetAndStartTimer();
for (int y = 0; y < yRes; y += bucketExtent) {
for (int x = 0; x < xRes; x += bucketExtent) {
buckets[0]->Start(x, y, std::min(x + bucketExtent, xRes),
std::min(y + bucketExtent, yRes));
rast->Rasterize(grids, nIntervals, buckets[0]);
buckets[0]->Resolve(image, xRes, yRes);
}
}
}
// Report total time for rasterization
double rastGCycles = GetElapsedMCycles() / 1024.;
printf(" %.3f billion cycles\n", rastGCycles);
// Write the image
char outName[256];
sprintf(outName, "%s_int%d_samp%d.ppm", sceneName, nIntervals,
nPixelSamples);
WritePPM(image, xRes, yRes, outName);
printf(" Wrote output image \"%s\"\n", outName);
// Compare to the "golden" image for correctness
char goldenName[256];
sprintf(goldenName, "golden/%s_%d.ppm", sceneName,
nPixelSamples);
if (!CompareToGolden(image, xRes, yRes, goldenName, outName))
++failures;
}
printf("\n");
for (int i = 0; i < nBuckets; ++i)
delete buckets[i];
delete[] image;
}
if (useTasks)
TasksCleanup();
delete rast;
return failures;
}
void MetropolisRenderer::Render(const Scene *scene) {
int x0, x1, y0, y1;
camera->film->GetPixelExtent(&x0, &x1, &y0, &y1);
int nPixels = (x1-x0) * (y1-y0);
float t0 = camera->shutterOpen;
float t1 = camera->shutterClose;
if (doDirectSeparately) {
// Compute direct lighting before Metropolis light transport
LDSampler sampler(x0, x1, y0, y1, directPixelSamples, t0, t1);
Sample *sample = new Sample(&sampler, directLighting, NULL, scene);
vector<Task *> directTasks;
int nDirectTasks = max(32 * NumSystemCores(),
(camera->film->xResolution * camera->film->yResolution) / (16*16));
nDirectTasks = RoundUpPow2(nDirectTasks);
ProgressReporter directProgress(nDirectTasks, "Direct Lighting");
for (int i = 0; i < nDirectTasks; ++i)
directTasks.push_back(new SamplerRendererTask(scene, this, camera,
&sampler, directProgress, sample, i, nDirectTasks));
std::reverse(directTasks.begin(), directTasks.end());
EnqueueTasks(directTasks);
WaitForAllTasks();
for (uint32_t i = 0; i < directTasks.size(); ++i)
delete directTasks[i];
delete sample;
directProgress.Done();
}
// Take initial set of samples to compute $b$
RNG rng(0);
MemoryArena arena;
vector<float> bootstrapSamples;
float sumContrib = 0.f;
bootstrapSamples.reserve(nBootstrap);
MLTSample sample(maxDepth);
for (int i = 0; i < nBootstrap; ++i) {
// Compute contribution for random sample for MLT bootstrapping
LargeStep(rng, &sample, maxDepth, x0, x1, y0, y1, t0, t1);
float contrib = I(L(scene, this, camera, arena, rng, maxDepth,
doDirectSeparately, sample), sample);
sumContrib += contrib;
bootstrapSamples.push_back(contrib);
arena.FreeAll();
}
float b = sumContrib / nBootstrap;
// Select initial sample from bootstrap samples
rng.Seed(0);
float contribOffset = rng.RandomFloat() * sumContrib;
sumContrib = 0.f;
MLTSample initialSample(maxDepth);
for (int i = 0; i < nBootstrap; ++i) {
LargeStep(rng, &initialSample, maxDepth, x0, x1, y0, y1, t0, t1);
sumContrib += bootstrapSamples[i];
if (contribOffset < sumContrib)
break;
}
// Launch tasks to generate Metropolis samples
if (scene->lights.size() > 0) {
int nTasks = int(nSamples / 50000);
nTasks = max(nTasks, 32 * NumSystemCores());
nTasks = min(nTasks, 32768);
nSamples = (nSamples / nTasks) * nTasks;
ProgressReporter progress(nTasks, "Metropolis");
vector<Task *> tasks;
Mutex *filmMutex = Mutex::Create();
for (int i = 0; i < nTasks; ++i)
tasks.push_back(new MLTTask(progress, i, int(nSamples/nTasks), nSamples,
nPixels, x0, x1, y0, y1, t0, t1, b, largeStepProbability, initialSample,
doDirectSeparately, maxConsecutiveRejects, maxDepth, scene, camera, this,
&nSamplesFinished, filmMutex));
EnqueueTasks(tasks);
WaitForAllTasks();
for (uint32_t i = 0; i < tasks.size(); ++i)
delete tasks[i];
progress.Done();
}
camera->film->WriteImage();
}