directional emitter

class directional_t : public wt::emitter::infinite_emitter_t

An emitter positioned at infinity, with a fixed direction and subtending a fixed solid angle from the scene.

Public Functions

inline directional_t(std::string id, const dir3_t &dir, std::shared_ptr<spectrum::spectrum_real_t> irradiance, solid_angle_t sa_at_traget, f_t emitter_phase_space_extent_scale = 1)
directional_t(const directional_t&) = default
directional_t(directional_t&&) = default
inline virtual bool is_delta_position() const noexcept override
inline virtual bool is_delta_direction() const noexcept override
inline spectral_irradiance_t spectral_irradiance(const wavenumber_t k) const noexcept
inline const auto &direction_to_emitter() const noexcept
inline virtual const spectrum::spectrum_real_t &emission_spectrum() const noexcept override

Returns the emitter’s emission spectrum.

inline virtual spectral_radiant_flux_t power(wavenumber_t k) const noexcept override

Computes total spectral power that arrives to an area.

inline virtual radiant_flux_t power(const range_t<wavenumber_t> &krange) const noexcept override

Computes total power, over a wavenumber range, that arrives to an area.

inline beam::sourcing_geometry_t sourcing_geometry(const wavenumber_t k) const noexcept
inline spectral_irradiance_beam_t Le(const ray_t &p, const wavenumber_t k) const noexcept

Source a beam from this light source.

Parameters:

k – wavenumber

inline virtual spectral_radiant_flux_stokes_t Li(const importance_flux_beam_t &beam, const intersection_surface_t *surface = nullptr) const noexcept override

Integrate a detector beam over the emitter.

Parameters:

beam – detection beam incident upon the emitter

virtual emitter_sample_t sample(sampler::sampler_t &sampler, const wavenumber_t k) const noexcept override

Samples an emission phase-space position (ray) on the light source.

Parameters:

k – wavenumber

virtual emitter_direct_sample_t sample_direct(sampler::sampler_t &sampler, const pqvec3_t &wp, const wavenumber_t k) const noexcept override

Samples a direct connection to a world position.

Parameters:

  • wp – world position

  • k – wavenumber

inline virtual area_sampling_pd_t pdf_target_position(const pqvec3_t &wp) const noexcept override

Sampling area PDF of a target scene position, sampled by the infinite emitter’s sample().

Parameters:

wp – sampled scene position

inline virtual solid_angle_sampling_pd_t pdf_direction(const pqvec3_t &p, const dir3_t &dir, const intersection_surface_t *surface = nullptr) const noexcept override

Sampling PDF of an emission direction from the light source.

Parameters:

  • p – position on light source

  • dir – emission direction

  • surface – emitter surface intersection record (should be nullptr)

inline virtual solid_angle_sampling_pd_t pdf_direct(const pqvec3_t &wp, const ray_t &r, const intersection_surface_t *surface = nullptr) const noexcept override

Sampling PDF of a direct connection.

Parameters:

  • wp – world position from which direct sampling was applied

  • sampled_r – sampled emitter phase-space position (ray)

  • sampled_surface – sampled surface for emitter samples that seat on a surface (should be nullptr)

Returns:

the solid angle density from wp

virtual scene::element::info_t description() const override

Public Static Functions

static std::unique_ptr<emitter_t> load(std::string id, scene::loader::loader_t *loader, const scene::loader::node_t &node, const wt::wt_context_t &context)