infinite emitters¶

directional emitter

class infinite_emitter_t : public wt::emitter::emitter_t

Generic interface for infinite emitters. Sampling of infinite emitters is slightly different compared with regular emitters. During construction, wt::scene_t populates the scene-wide bounding AABB world_aabb of all infinite emitters. The infinite emitters’ sampling API changes as follows:

wt::emitter::emitter_t::sample_position() and wt::emitter::emitter_t::pdf_position() are unused and return 0.
wt::emitter::emitter_t::sample() samples with respect to positions within the world_aabb, and not with respect to positions upon the emitter.
An alternative density query wt::emitter::infinite_emitter_t::pdf_target_position() provides the area sampling density for sampled world positions.

Subclassed by wt::emitter::directional_t

Public Functions

inline infinite_emitter_t(std::string id, f_t emitter_phase_space_extent_scale = 1)

infinite_emitter_t(const infinite_emitter_t&) = default

infinite_emitter_t(infinite_emitter_t&&) = default

inline virtual bool is_infinite_emitter() const noexcept final

virtual area_sampling_pd_t pdf_target_position(const pqvec3_t &wp) const noexcept = 0

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

Parameters:: wp – sampled scene position

inline virtual position_sample_t sample_position(sampler::sampler_t &sampler) const noexcept final: Samples an emission phase-space position (ray) on the light source. Not implemented for infinite emitters.

inline virtual area_sampling_pd_t pdf_position(const pqvec3_t &p, const intersection_surface_t *surface = nullptr) const noexcept final: Sampling PDF of an emission position on the light source. Not implemented for infinite emitters.

Friends

friend class wt::scene_t