def Li(self, scene, renderer: Renderer, r: Ray, intersection: Intersection, sample: Sample) -> Spectrum:
# Declare common path integration variables
pathThroughput = Spectrum(1.0)
L = Spectrum(0.0)
ray = deepcopy(r)
specularBounce = False
localIsect = Intersection()
isectp = intersection
bounces = 0
while True:
# Possibly add emitted light at path vertex
if bounces == 0 or specularBounce:
L += pathThroughput * isectp.Le(-ray.direction)
# Sample illumination from lights to find path contribution
bsdf = isectp.get_bsdf(ray)
p = bsdf.dgShading.point
n = bsdf.dgShading.normal
wo = -ray.direction
if bounces < self.maxDepth:
L += pathThroughput * UniformSampleOneLight(scene, renderer, p, n, wo, ray.time, bsdf, sample,
self.lightSampleOffsets[bounces],
self.bsdfSampleOffsets[bounces],
self.lightNumOffset[bounces])
else:
L += pathThroughput * UniformSampleOneLight(scene, renderer, p, n, wo, ray.time, bsdf, sample)
# Sample BSDF to get new path direction
# Get _outgoingBSDFSample_ for sampling new path direction
if bounces < self.maxDepth:
outgoingBSDFSample = BSDFSample.create_from_sample(sample, self.pathSampleOffsets[bounces], 0)
else:
outgoingBSDFSample = BSDFSample.create_from_random()
wi, pdf, flags, f = bsdf.Sample_f(wo, outgoingBSDFSample, BxDFType.BSDF_ALL)
if f.get_is_black() or pdf == 0.0:
break
specularBounce = (flags & BxDFType.BSDF_SPECULAR) != 0
pathThroughput *= f * math.fabs(Vector3d.dot(wi, n)) / pdf
ray = Ray(p, wi, 0.01, ray.max_t)
# Possibly terminate the path
if bounces > 3:
continueProbability = min(0.5, pathThroughput.y())
if random() > continueProbability:
break
pathThroughput /= continueProbability
if bounces == self.maxDepth:
break
# Find next vertex of path
if not scene.get_intersection(ray, localIsect):
if specularBounce:
for i in range(scene.lights.size()):
L += pathThroughput * scene.lights[i].get_Le(ray)
break
# pathThroughput *= renderer->Transmittance(scene, ray, NULL, rng, arena);
isectp = localIsect
bounces += 1
return L
def run(self):
"""Execute the task."""
print "executing task %d/%d" % (self.task_num, self.task_count)
# get sub-sampler for SamplerRendererTask
sampler = self.main_sampler.get_sub_sampler(self.task_num,
self.task_count)
if not sampler:
return
# Declare local variables used for rendering loop
rng = RNG(self.task_num)
# allocate space for samples and intersections
max_samples = sampler.maximum_sample_count()
samples = self.orig_sample.duplicate(max_samples)
rays = [None] * max_samples
Ls = [None] * max_samples
Ts = [None] * max_samples
isects = [] # Intersection[max_samples]
for i in range(max_samples):
isects.append(Intersection())
# get samples from Sampler and update image
while True:
sample_count = sampler.get_more_samples(samples, rng)
# if no more samples to compute, exit
if sample_count <= 0:
break
# generate camera rays and compute radiance along rays
for i in range(sample_count):
# find camera ray for samples[i]
ray_weight, ray_diff = self.camera.generate_ray_differential(
samples[i])
rays[i] = ray_diff
coeff = 1.0 / math.sqrt(sampler.samples_per_pixel)
ray_diff.scale_differentials(coeff)
# evaluate radiance along camera ray
if ray_weight > 0.0:
radiance, intersection, Ts_i = \
self.renderer.Li(self.scene,
ray_diff,
samples[i],
rng,
isects[i])
Ls_i = ray_weight * radiance
else:
Ls_i = Spectrum(0.0)
Ts_i = Spectrum(1.0)
Ls[i] = Ls_i
Ts[i] = Ts_i
# check for unexpected radiance values
if Ls_i.has_nan():
logger.error(
"Not-a-number radiance value returned for image sample. Setting to black."
)
Ls_i = Spectrum(0.0)
elif Ls_i.y() < -1e-5:
logger.error(
"Negative luminance value, %f, returned for image sample. Setting to black."
% Ls_i.y())
Ls_i = Spectrum(0.0)
elif Ls_i.y() == float('inf'):
logger.error(
"Infinite luminance value returned for image sample. Setting to black."
)
Ls_i = Spectrum(0.0)
# report sample results to Sampler, add contributions to image
if sampler.report_results(samples, rays, Ls, isects, sample_count):
for i in range(sample_count):
self.camera.film.add_sample(samples[i], Ls[i])
# clean up after SamplerRendererTask is done with its image region
pass
def run(self):
"""Execute the task."""
print "executing task %d/%d" % (self.task_num, self.task_count)
# get sub-sampler for SamplerRendererTask
sampler = self.main_sampler.get_sub_sampler(self.task_num,
self.task_count)
if not sampler:
return
# Declare local variables used for rendering loop
rng = RNG(self.task_num)
# allocate space for samples and intersections
max_samples = sampler.maximum_sample_count()
samples = self.orig_sample.duplicate(max_samples)
rays = [None] * max_samples
Ls = [None] * max_samples
Ts = [None] * max_samples
isects = [] # Intersection[max_samples]
for i in range(max_samples):
isects.append(Intersection())
# get samples from Sampler and update image
while True:
sample_count = sampler.get_more_samples(samples, rng)
# if no more samples to compute, exit
if sample_count <= 0:
break
# generate camera rays and compute radiance along rays
for i in range(sample_count):
# find camera ray for samples[i]
ray_weight, ray_diff = self.camera.generate_ray_differential(samples[i])
rays[i] = ray_diff
coeff = 1.0 / math.sqrt(sampler.samples_per_pixel)
ray_diff.scale_differentials(coeff)
# evaluate radiance along camera ray
if ray_weight > 0.0:
radiance, intersection, Ts_i = \
self.renderer.Li(self.scene,
ray_diff,
samples[i],
rng,
isects[i])
Ls_i = ray_weight * radiance
else:
Ls_i = Spectrum(0.0)
Ts_i = Spectrum(1.0)
Ls[i] = Ls_i
Ts[i] = Ts_i
# check for unexpected radiance values
if Ls_i.has_nan():
logger.error(
"Not-a-number radiance value returned for image sample. Setting to black.")
Ls_i = Spectrum(0.0)
elif Ls_i.y() < -1e-5:
logger.error(
"Negative luminance value, %f, returned for image sample. Setting to black." % Ls_i.y())
Ls_i = Spectrum(0.0)
elif Ls_i.y() == float('inf'):
logger.error(
"Infinite luminance value returned for image sample. Setting to black.")
Ls_i = Spectrum(0.0)
# report sample results to Sampler, add contributions to image
if sampler.report_results(samples, rays, Ls, isects, sample_count):
for i in range(sample_count):
self.camera.film.add_sample(samples[i], Ls[i])
# clean up after SamplerRendererTask is done with its image region
pass