void DirectLightingIntegrator::compute_outgoing_radiance_combined_sampling_low_variance(
SamplingContext& sampling_context,
const Dual3d& outgoing,
Spectrum& radiance,
SpectrumStack& aovs) const
{
compute_outgoing_radiance_bsdf_sampling(
sampling_context,
MISPower2,
outgoing,
radiance,
aovs);
Spectrum radiance_light_sampling;
SpectrumStack aovs_light_sampling(aovs.size());
compute_outgoing_radiance_light_sampling_low_variance(
sampling_context,
MISPower2,
outgoing,
radiance_light_sampling,
aovs_light_sampling);
radiance += radiance_light_sampling;
aovs += aovs_light_sampling;
}
void add_back_lighting(
const InputValues& values,
SamplingContext& sampling_context,
const PixelContext& pixel_context,
const ShadingContext& shading_context,
const ShadingPoint& shading_point,
Spectrum& radiance,
SpectrumStack& aovs) const
{
const Vector3d& p = shading_point.get_point();
const Vector3d& n = shading_point.get_original_shading_normal();
const Vector3d& d = shading_point.get_ray().m_dir;
// Construct a ray perpendicular to the other side of the surface.
ShadingRay back_ray(shading_point.get_ray());
back_ray.m_tmax *= norm(d);
back_ray.m_dir = dot(d, n) > 0.0 ? -n : n;
back_ray.m_org = p - back_ray.m_tmax * back_ray.m_dir;
ShadingPoint back_shading_point(shading_point);
back_shading_point.set_ray(back_ray);
Spectrum back_radiance(0.0f);
SpectrumStack back_aovs(aovs.size(), 0.0f);
// Compute back lighting.
for (size_t i = 0; i < m_back_lighting_samples; ++i)
{
shading_context.get_lighting_engine()->compute_lighting(
sampling_context,
pixel_context,
shading_context,
back_shading_point,
back_radiance,
back_aovs);
}
// Apply translucency factor.
back_radiance *= values.m_translucency;
back_aovs *= values.m_translucency;
// Divide by the number of samples.
const float rcp_sample_count = 1.0f / static_cast<float>(m_back_lighting_samples);
back_radiance *= rcp_sample_count;
back_aovs *= rcp_sample_count;
// Add back lighting contribution.
radiance += back_radiance;
aovs += back_aovs;
}
void DirectLightingIntegrator::sample_bsdf_and_lights_low_variance(
SamplingContext& sampling_context,
Spectrum& radiance,
SpectrumStack& aovs)
{
sample_bsdf(
sampling_context,
DirectLightingIntegrator::mis_power2,
radiance,
aovs);
Spectrum radiance_light_sampling;
SpectrumStack aovs_light_sampling(aovs.size());
sample_lights_low_variance(
sampling_context,
DirectLightingIntegrator::mis_power2,
radiance_light_sampling,
aovs_light_sampling);
radiance += radiance_light_sampling;
aovs += aovs_light_sampling;
}