void DirectLightingIntegrator::compute_outgoing_radiance_bsdf_sampling(
SamplingContext& sampling_context,
const MISHeuristic mis_heuristic,
const Dual3d& outgoing,
Spectrum& radiance,
SpectrumStack& aovs) const
{
radiance.set(0.0f);
aovs.set(0.0f);
if (m_light_sampler.get_emitting_triangle_count() == 0)
return;
for (size_t i = 0; i < m_bsdf_sample_count; ++i)
{
take_single_bsdf_sample(
sampling_context,
mis_heuristic,
outgoing,
radiance,
aovs);
}
if (m_bsdf_sample_count > 1)
{
const float rcp_bsdf_sample_count = 1.0f / m_bsdf_sample_count;
radiance *= rcp_bsdf_sample_count;
aovs *= rcp_bsdf_sample_count;
}
}
void DirectLightingIntegrator::compute_outgoing_radiance_light_sampling(
SamplingContext& sampling_context,
const MISHeuristic mis_heuristic,
const Dual3d& outgoing,
Spectrum& radiance,
SpectrumStack& aovs) const
{
radiance.set(0.0f);
aovs.set(0.0f);
sampling_context.split_in_place(3, m_light_sample_count);
for (size_t i = 0; i < m_light_sample_count; ++i)
{
take_single_light_sample(
sampling_context,
mis_heuristic,
outgoing,
radiance,
aovs);
}
if (m_light_sample_count > 1)
{
const float rcp_light_sample_count = 1.0f / m_light_sample_count;
radiance *= rcp_light_sample_count;
aovs *= rcp_light_sample_count;
}
}
void DirectLightingIntegrator::take_single_bsdf_or_light_sample(
SamplingContext& sampling_context,
Spectrum& radiance,
SpectrumStack& aovs)
{
radiance.set(0.0f);
aovs.set(0.0f);
sampling_context.split_in_place(1, 1);
if (sampling_context.next_double2() < 0.5)
{
sampling_context.split_in_place(3, m_light_sample_count);
take_single_light_sample(
sampling_context,
DirectLightingIntegrator::mis_balance,
radiance,
aovs);
}
else
{
take_single_bsdf_sample(
sampling_context,
DirectLightingIntegrator::mis_balance,
radiance,
aovs);
}
}
void DirectLightingIntegrator::compute_outgoing_radiance_single_sample(
SamplingContext& sampling_context,
const Dual3d& outgoing,
Spectrum& radiance,
SpectrumStack& aovs) const
{
radiance.set(0.0f);
aovs.set(0.0f);
if (m_light_sampler.get_emitting_triangle_count() > 0)
{
sampling_context.split_in_place(1, 1);
if (sampling_context.next_double2() < 0.5)
{
sampling_context.split_in_place(3, 1);
take_single_light_sample(
sampling_context,
MISBalance,
outgoing,
radiance,
aovs);
}
else
{
take_single_bsdf_sample(
sampling_context,
MISBalance,
outgoing,
radiance,
aovs);
}
radiance *= 2.0f;
aovs *= 2.0f;
}
else
{
take_single_light_sample(
sampling_context,
MISNone,
outgoing,
radiance,
aovs);
}
}
void DirectLightingIntegrator::compute_outgoing_radiance_light_sampling_low_variance(
SamplingContext& sampling_context,
const MISHeuristic mis_heuristic,
const Dual3d& outgoing,
Spectrum& radiance,
SpectrumStack& aovs) const
{
radiance.set(0.0f);
aovs.set(0.0f);
// todo: if we had a way to know that a BSDF is purely specular, we could
// immediately return black here since there will be no contribution from
// such a BSDF.
// Sample emitting triangles.
if (m_light_sampler.get_emitting_triangle_count() > 0)
{
sampling_context.split_in_place(3, m_light_sample_count);
for (size_t i = 0; i < m_light_sample_count; ++i)
{
const Vector3d s = sampling_context.next_vector2<3>();
LightSample sample;
m_light_sampler.sample_emitting_triangles(m_time, s, sample);
add_emitting_triangle_sample_contribution(
sample,
mis_heuristic,
outgoing,
radiance,
aovs);
}
if (m_light_sample_count > 1)
{
const float rcp_light_sample_count = 1.0f / m_light_sample_count;
radiance *= rcp_light_sample_count;
aovs *= rcp_light_sample_count;
}
}
// Sample non-physical light sources.
const size_t light_count = m_light_sampler.get_non_physical_light_count();
if (light_count > 0)
{
sampling_context.split_in_place(2, light_count);
for (size_t i = 0; i < light_count; ++i)
{
const Vector2d s = sampling_context.next_vector2<2>();
LightSample sample;
m_light_sampler.sample_non_physical_light(m_time, s, i, sample);
add_non_physical_light_sample_contribution(
sample,
outgoing,
radiance,
aovs);
}
}
}