void DiffusePRTIntegrator::Preprocess(const Scene *scene,
const Camera *camera, const Renderer *renderer) {
BBox bbox = scene->WorldBound();
Point p = .5f * bbox.pMin + .5f * bbox.pMax;
RNG rng;
MemoryArena arena;
SHProjectIncidentDirectRadiance(p, 0.f, camera->shutterOpen, arena,
scene, false, lmax, rng, c_in);
}
void GlossyPRTIntegrator::Preprocess(const Scene *scene,
const Camera *camera, const Renderer *renderer) {
// Project direct lighting into SH for _GlossyPRTIntegrator_
BBox bbox = scene->WorldBound();
Point p = .5f * bbox.pMin + .5f * bbox.pMax;
RNG rng;
MemoryArena arena;
c_in = new Spectrum[SHTerms(lmax)];
SHProjectIncidentDirectRadiance(p, 0.f, camera->shutterOpen, arena,
scene, false, lmax, rng, c_in);
// Compute glossy BSDF matrix for PRT
B = new Spectrum[SHTerms(lmax)*SHTerms(lmax)];
SHComputeBSDFMatrix(Kd, Ks, roughness, rng, 1024, lmax, B);
}
void CreateRadProbeTask::Run() {
// Compute region in which to compute incident radiance probes
int sx = pointNum % nProbes[0];
int sy = (pointNum / nProbes[0]) % nProbes[1];
int sz = pointNum / (nProbes[0] * nProbes[1]);
Assert(sx >= 0 && sx < nProbes[0]);
Assert(sy >= 0 && sy < nProbes[1]);
Assert(sz >= 0 && sz < nProbes[2]);
float tx0 = float(sx) / nProbes[0], tx1 = float(sx+1) / nProbes[0];
float ty0 = float(sy) / nProbes[1], ty1 = float(sy+1) / nProbes[1];
float tz0 = float(sz) / nProbes[2], tz1 = float(sz+1) / nProbes[2];
BBox b(bbox.Lerp(tx0, ty0, tz0), bbox.Lerp(tx1, ty1, tz1));
// Initialize common variables for _CreateRadProbeTask::Run()_
RNG rng(pointNum);
Spectrum *c_probe = new Spectrum[SHTerms(lmax)];
MemoryArena arena;
uint32_t nFound = 0, lastVisibleOffset = 0;
for (int i = 0; i < 256; ++i) {
if (nFound == 32) break;
// Try to compute radiance probe contribution at _i_th sample point
// Compute _i_th candidate point _p_ in cell's bounding box
float dx = RadicalInverse(i+1, 2);
float dy = RadicalInverse(i+1, 3);
float dz = RadicalInverse(i+1, 5);
Point p = b.Lerp(dx, dy, dz);
// Skip point _p_ if not indirectly visible from camera
if (scene->IntersectP(Ray(surfacePoints[lastVisibleOffset],
p - surfacePoints[lastVisibleOffset],
1e-4f, 1.f, time))) {
uint32_t j;
// See if point is visible to any element of _surfacePoints_
for (j = 0; j < surfacePoints.size(); ++j)
if (!scene->IntersectP(Ray(surfacePoints[j], p - surfacePoints[j],
1e-4f, 1.f, time))) {
lastVisibleOffset = j;
break;
}
if (j == surfacePoints.size())
continue;
}
++nFound;
// Compute SH coefficients of incident radiance at point _p_
if (includeDirectInProbes) {
for (int i = 0; i < SHTerms(lmax); ++i)
c_probe[i] = 0.f;
SHProjectIncidentDirectRadiance(p, 0.f, time, arena, scene,
true, lmax, rng, c_probe);
for (int i = 0; i < SHTerms(lmax); ++i)
c_in[i] += c_probe[i];
}
if (includeIndirectInProbes) {
for (int i = 0; i < SHTerms(lmax); ++i)
c_probe[i] = 0.f;
SHProjectIncidentIndirectRadiance(p, 0.f, time, renderer,
origSample, scene, lmax, rng, nIndirSamples, c_probe);
for (int i = 0; i < SHTerms(lmax); ++i)
c_in[i] += c_probe[i];
}
arena.FreeAll();
}
// Compute final average value for probe and cleanup
if (nFound > 0)
for (int i = 0; i < SHTerms(lmax); ++i)
c_in[i] /= nFound;
delete[] c_probe;
prog.Update();
}
