AggregateBSDF Class Reference

Linear combination of different BSDF implementations, where the coefficients are determined either a priori (inherent property described in scenefile) or via a texture map lookup. More...

#include <AggregateBSDF.h>

Inheritance diagram for AggregateBSDF:

List of all members.

Public Member Functions

Constructors

AggregateBSDF (SurfacePoint &pt, Material *parent=NULL)

virtual ~AggregateBSDF ()

Initialization

virtual void init ()

Initializes this aggregate BSDF for sampling by selecting one of the possible child BSDFs.

Main usage interface

virtual void setWi (const Vector3 &wi)

Sets the incident vector, wi, for this BSDF. All BSDF sampling is with respect to the current value of wi.

virtual Event sample ()

Samples an exitent vector at the given surface point.

virtual real_t getPdf (const Event &event)

virtual SpectralSampleSet getBSDF (const Vector3 &wi, const Vector3 &wo)

Evaluates the spectral BSDF at the given surface point with respect to the out vector, 'wo', at the underlying surface point and given incident vector, 'wi'.

virtual bool isSpecular (Event &event) const

Protected Attributes

BSDFList m_bsdfs

unsigned m_bsdf

Detailed Description

Linear combination of different BSDF implementations, where the coefficients are determined either a priori (inherent property described in scenefile) or via a texture map lookup.

Author:: Travis Fischer (fisch0920@gmail.com)
Matthew Jacobs (jacobs.mh@gmail.com)

Date:: Fall 2008

Definition at line 29 of file AggregateBSDF.h.

Constructor & Destructor Documentation

AggregateBSDF::AggregateBSDF	(	SurfacePoint &	pt,
		Material *	parent = `NULL`
	)			`[inline, explicit]`

Definition at line 34 of file AggregateBSDF.h.

AggregateBSDF::~AggregateBSDF ( ) [virtual]

Definition at line 17 of file AggregateBSDF.cpp.

Member Function Documentation

void AggregateBSDF::init ( ) [virtual]

Initializes this aggregate BSDF for sampling by selecting one of the possible child BSDFs.

Reimplemented from BSDF.

Definition at line 23 of file AggregateBSDF.cpp.

void AggregateBSDF::setWi ( const Vector3 & wi ) [virtual]

Sets the incident vector, wi, for this BSDF. All BSDF sampling is with respect to the current value of wi.

Reimplemented from BSDF.

Definition at line 54 of file AggregateBSDF.cpp.

Event AggregateBSDF::sample ( ) [virtual]

Samples an exitent vector at the given surface point.

Returns:: the sampled vector as a Vector3 wrapped in an Event object

Note:: returns Vector3::zero() if no exitent vector was sampled (to model a certain probability of absorption, for instance)

Example usage:


    const Event &event = bsdf.sample();
    const Vector3 &wo  = event.getValue();
    const real_t pd    = bsdf.getPdf(event);        // p(x) probability
    const SpectralSampleSet &fs = bsdf.getBSDF(wo); // f(x) reflectivity

Implements BSDF.

Definition at line 61 of file AggregateBSDF.cpp.

real_t AggregateBSDF::getPdf ( const Event & event ) [virtual]

Returns:: the probability density of having sampled the given out out vector event with respect to whatever underlying sampling strategy is being used to sample the BSDF

Note:: probability density is assumed to be with respect to projected solid angle (the conversion from solid angle to projected solid angle involves dividing the solid angle density by the absolute value of the cosine of the angle between the local surface normal and the exitant vector in event)

Implements BSDF.

Definition at line 66 of file AggregateBSDF.cpp.

SpectralSampleSet AggregateBSDF::getBSDF	(	const Vector3 &	wi,
		const Vector3 &	wo
	)			`[virtual]`

Evaluates the spectral BSDF at the given surface point with respect to the out vector, 'wo', at the underlying surface point and given incident vector, 'wi'.

Returns:: the spectral radiance leaving in direction wo, per unit of irradiance arriving from wi (unitless fraction in [0, 1])

Implements BSDF.

Definition at line 73 of file AggregateBSDF.cpp.

bool AggregateBSDF::isSpecular ( Event & ) const [virtual]

Returns:: true iff this BSDF is non-zero over a set of solid angles with measure zero (measured with respect to solid angle)

Note:

a perfectly specular material has a dirac distribution for its reflectance, and therefore needs special consideration when sampling the BRDF for simulation purposes

the default implementation returns false because perfectly specular surfaces don't occur that often in real life, though they abound in computer graphics (due to their ease of simulation)

implementations are free to use the given Event's metadata to determine whether or not it represents a specular event

Reimplemented from BSDF.

Definition at line 77 of file AggregateBSDF.cpp.

Member Data Documentation

BSDFList AggregateBSDF::m_bsdfs [protected]

Definition at line 70 of file AggregateBSDF.h.

unsigned AggregateBSDF::m_bsdf [protected]

Definition at line 72 of file AggregateBSDF.h.

The documentation for this class was generated from the following files:


Public Member Functions
Constructors
	AggregateBSDF (SurfacePoint &pt, Material *parent=NULL)
virtual	~AggregateBSDF ()
Initialization
virtual void	init ()
	Initializes this aggregate BSDF for sampling by selecting one of the possible child BSDFs.
Main usage interface
virtual void	setWi (const Vector3 &wi)
	Sets the incident vector, wi, for this BSDF. All BSDF sampling is with respect to the current value of wi.
virtual Event	sample ()
	Samples an exitent vector at the given surface point.
virtual real_t	getPdf (const Event &event)
virtual SpectralSampleSet	getBSDF (const Vector3 &wi, const Vector3 &wo)
	Evaluates the spectral BSDF at the given surface point with respect to the out vector, 'wo', at the underlying surface point and given incident vector, 'wi'.
virtual bool	isSpecular (Event &event) const
Protected Attributes
BSDFList	m_bsdfs
unsigned	m_bsdf