PbrGgx< REAL > Class Template Reference

Inheritance diagram for PbrGgx< REAL >:

Public Member Functions
void	configure (REAL roughness)
virtual REAL	get_roughness () const final
virtual REAL	sample (const GMathVec3< REAL > &wi_local, REAL u, REAL v, GMathVec3< REAL > &h_local, REAL &weight) const final
	sample Uses the provided samples in the domain [0,1] in order to generate a candidate outgoing direction. Once this vector is computed, the sample function also computes and returns the PDF of the distribution function for the candidate normal.
virtual REAL	evaluate (const GMathVec3< REAL > &wi_local, const GMathVec3< REAL > &h_local, REAL &weight) const final
	evaluate Compute the ndf and return the pdf of the current sample
virtual REAL	lambda (const GMathVec3< REAL > &w_local, bool is_wo) const final
	lambda function used to evaluate geometric shadowing and masking of the microfacet distribution

Detailed Description

template<typename REAL = double>
class PbrGgx< REAL >

class GGX This implementation of a microfacet model is based on the anisotropic GGX derivation found in the Disney Physical Shading paper (Burley), found in appendix B.

Member Function Documentation

template<typename REAL >

REAL PbrGgx< REAL >::evaluate ( const GMathVec3< REAL > &  wi_local, const GMathVec3< REAL > &  h_local, REAL &  weight  ) const

finalvirtual

evaluate Compute the ndf and return the pdf of the current sample

Parameters

wi_local	the incoming direction at the surface point, in local space
h_local	the sampled normal computed by the function, in local space
weight	the output ratio of the normal distribution function and the PDF

Returns

the pdf

Implements PbrMicrofacetDistribution< REAL >.

template<typename REAL >

REAL PbrGgx< REAL >::lambda ( const GMathVec3< REAL > &  w_local, bool  is_wo  ) const

finalvirtual

lambda function used to evaluate geometric shadowing and masking of the microfacet distribution

Parameters

w_local	the ray direction in local space (incoming or outgoing)
h_local	the half angle vector in local space
is_wo	If true it means that w_local is the incomming direction at the surface point else it is the outgoing direction

Returns

a term used to compute the shadowing and masking function

Implements PbrMicrofacetDistribution< REAL >.

template<typename REAL >

REAL PbrGgx< REAL >::sample ( const GMathVec3< REAL > &  wi_local, REAL  u, REAL  v, GMathVec3< REAL > &  h_local, REAL &  weight  ) const

finalvirtual

sample Uses the provided samples in the domain [0,1] in order to generate a candidate outgoing direction. Once this vector is computed, the sample function also computes and returns the PDF of the distribution function for the candidate normal.

Parameters

wi_local	the incoming direction at the surface point, in local space
u	the 2D sample
v	the 2D sample
h_local	the sampled normal computed by the function, in local space
weight	the output ratio of the normal distribution function and the PDF

Returns

the PDF of the distribution function for the candidate normal.

Implements PbrMicrofacetDistribution< REAL >.