normal mapped

class normalmap_t : public wt::bsdf::bsdf_t

Normal mapping BSDF. A nested texture encodes the shading normal variations ([.5,.5,1.] encodes an unchanged normal). Bitmap textures should use linear colour conding.

Public Functions

inline normalmap_t(std::string id, std::shared_ptr<texture::texture_t> normalmap, std::shared_ptr<bsdf_t> nested, bool flip)
normalmap_t(normalmap_t&&) = default
inline virtual frame_t shading_frame(const texture::texture_query_t &tquery, const mesh::surface_differentials_t &tangent_frame, const dir3_t &ns) const noexcept override

Constructs a shading frame in world space. This is useful for BSDFs that perturb the shading frame, like normal or bump maps.

Parameters:

  • tquery – texture query data.

  • tangent_frame – mesh tangent frame at intersection.

  • ns – interpolated shading normal at intersection.

inline virtual std::optional<f_t> albedo(const wavenumber_t k) const noexcept override

Spectral albedo. Returns std::nullopt when albedo cannot be computed.

Parameters:

k – wavenumber

inline virtual lobe_mask_t lobes(wavenumber_t k) const noexcept override

Returns mask of all available lobes for this BSDF at particular wavenumber.

inline virtual bool is_delta_only(wavenumber_t k) const noexcept override

Does this BSDF comprise of only delta lobes?

inline virtual bool is_delta_lobe(wavenumber_t k, std::uint32_t lobe) const noexcept override

Is a lobe a delta lobe?

inline virtual bool needs_interaction_footprint() const noexcept override

Returns true for BSDF that make use of the surface interaction footprint data.

inline virtual bsdf_result_t f(const dir3_t &wi, const dir3_t &wo, const bsdf_query_t &query) const noexcept override

Evaluates the BSDF. Accounts for the cosine foreshortening term.

inline virtual std::optional<bsdf_sample_t> sample(const dir3_t &wi, const bsdf_query_t &query, sampler::sampler_t &sampler) const noexcept override

Samples the BSDF. The returned weight is bsdf/pdf.

Parameters:

S – normalized Stokes parameters vector that describes the polarimetric properties of incident radiation.

inline virtual solid_angle_density_t pdf(const dir3_t &wi, const dir3_t &wo, const bsdf_query_t &query) const noexcept override

Provides the sample density.

Parameters:

S – normalized Stokes parameters vector that describes the polarimetric properties of incident radiation.

inline virtual f_t eta(const dir3_t &wi, const dir3_t &wo, const wavenumber_t k) const noexcept override

Computes the refractive-index ratio: eta at exit / eta at entry.

Parameters:

k – wavenumber

inline const auto &nested_bsdf() const noexcept
virtual scene::element::info_t description() const override

Public Static Functions

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