Abstract radiance emitter interface. More...

#include <mitsuba/render/emitter.h>

Inheritance diagram for mitsuba::Emitter:

Public Types
enum	EEmitterFlags { EEnvironmentEmitter = 0x010 }
	This list of flags is used to additionally characterize and classify the response functions of different types of sensors. More...

Public Types inherited from mitsuba::AbstractEmitter
enum	EEmitterType { EDeltaDirection = 0x01, EDeltaPosition = 0x02, EOnSurface = 0x04 }
	Flags used to classify the emission profile of different types of emitters. More...

Public Member Functions
virtual const Class *	getClass () const
	Retrieve this object's class. More...

Additional emitter-related sampling and query functions
virtual Spectrum	eval (const Intersection &its, const Vector &d) const
	Return the radiant emittance for the given surface intersection. More...

virtual Spectrum	sampleRay (Ray &ray, const Point2 &spatialSample, const Point2 &directionalSample, Float time) const
	Importance sample a ray according to the emission profile. More...

Miscellaneous
Float	getSamplingWeight () const
	Return the luminaire's sampling weight. More...

virtual ref< Bitmap >	getBitmap (const Vector2i &sizeHint=Vector2i(-1,-1)) const
	Return a bitmap representation of the emitter. More...

virtual void	serialize (Stream stream, InstanceManager manager) const
	Serialize this emitter to a binary data stream. More...

virtual bool	isCompound () const
	Is this a compound emitter consisting of several sub-objects? More...

virtual Emitter *	getElement (size_t index)
	Return a sub-element of a compound emitter. More...

Functionality related to environment emitters
bool	isEnvironmentEmitter () const
	Is this an environment emitter? (e.g. an HDRI environment map?) More...

virtual Spectrum	evalEnvironment (const RayDifferential &ray) const
	Return the radiant emittance from an environment emitter. More...

virtual bool	fillDirectSamplingRecord (DirectSamplingRecord &dRec, const Ray &ray) const
	Fill out a data record that can be used to query the direct illumination sampling density of an environment emitter. More...

Public Member Functions inherited from mitsuba::AbstractEmitter
virtual Spectrum	samplePosition (PositionSamplingRecord &pRec, const Point2 &sample, const Point2 *extra=NULL) const
	Importance sample the spatial component of the emission profile. More...

virtual Spectrum	sampleDirection (DirectionSamplingRecord &dRec, PositionSamplingRecord &pRec, const Point2 &sample, const Point2 *extra=NULL) const
	Conditioned on the spatial component, importance sample the directional part of the emission profile. More...

virtual Spectrum	sampleDirect (DirectSamplingRecord &dRec, const Point2 &sample) const
	Direct sampling: given a reference point in the scene, sample an emitter position that contributes towards it. More...

virtual Spectrum	evalPosition (const PositionSamplingRecord &pRec) const
	Evaluate the spatial component of the emission profile. More...

virtual Spectrum	evalDirection (const DirectionSamplingRecord &dRec, const PositionSamplingRecord &pRec) const
	Evaluate the directional component of the emission profile. More...

virtual Float	pdfPosition (const PositionSamplingRecord &pRec) const
	Evaluate the spatial component of the sampling density implemented by the samplePosition() method. More...

virtual Float	pdfDirection (const DirectionSamplingRecord &dRec, const PositionSamplingRecord &pRec) const
	Evaluate the directional component of the sampling density implemented by the sampleDirection() method. More...

virtual Float	pdfDirect (const DirectSamplingRecord &dRec) const
	Evaluate the probability density of the direct sampling method implemented by the sampleDirect() method. More...

uint32_t	getType () const
	Return a listing of classification flags combined using binary OR. More...

const AnimatedTransform *	getWorldTransform () const
	Return the local space to world space transformation. More...

void	setWorldTransform (AnimatedTransform *trafo)
	Set the local space to world space transformation. More...

bool	needsPositionSample () const
	Does the method samplePosition() require a uniformly distributed sample for the spatial component? More...

bool	needsDirectionSample () const
	Does the method sampleDirection() require a uniformly distributed sample for the direction component? More...

bool	isOnSurface () const
	Does the emitter lie on some kind of surface? More...

bool	isDegenerate () const
	Does the sensor have a degenerate directional or spatial distribution? More...

bool	needsDirectSample () const
	Does the method sampleDirect() require a uniformly distributed sample? More...

EMeasure	getDirectMeasure () const
	Return the measure associated with the sampleDirect() operation. More...

Medium *	getMedium ()
	Return a pointer to the medium that surrounds the emitter. More...

const Medium *	getMedium () const
	Return a pointer to the medium that surrounds the emitter (const version) More...

Shape *	getShape ()
	Return the shape, to which the emitter is currently attached. More...

const Shape *	getShape () const
	Return the shape, to which the emitter is currently attached (const version) More...

virtual ref< Shape >	createShape (const Scene *scene)
	Create a special shape that represents the emitter. More...

virtual AABB	getAABB () const =0
	Return an axis-aligned box bounding the spatial extents of the emitter. More...

void	setMedium (Medium *medium)
	Set the medium that surrounds the emitter. More...

virtual void	addChild (const std::string &name, ConfigurableObject *child)
	Add a child ConfigurableObject. More...

void	addChild (ConfigurableObject *child)
	Add an unnamed child. More...

Public Member Functions inherited from mitsuba::ConfigurableObject
virtual void	setParent (ConfigurableObject *parent)
	Notify the ConfigurableObject instance about its parent object. More...

void	addChild (ConfigurableObject *child)
	Add an unnamed child. More...

virtual void	configure ()
	Configure the object (called once after construction and addition of all child ConfigurableObject instances)) More...

const std::string &	getID () const
	Return the identifier associated with this instance (or "unnamed") More...

void	setID (const std::string &name)
	Set the identifier associated with this instance. More...

const Properties &	getProperties () const
	Return the properties object that was originally used to create this instance. More...

Public Member Functions inherited from mitsuba::SerializableObject
	SerializableObject (Stream stream, InstanceManager manager)
	Unserialize a serializable object. More...

Public Member Functions inherited from Object
	Object ()
	Construct a new object. More...

int	getRefCount () const
	Return the current reference count. More...

void	incRef () const
	Increase the reference count of the object by one. More...

void	decRef (bool autoDeallocate=true) const
	Decrease the reference count of the object and possibly deallocate it. More...

virtual std::string	toString () const
	Return a human-readable string representation of the object's contents. More...

Public Member Functions inherited from mitsuba::HWResource
virtual Shader *	createShader (Renderer *renderer) const

virtual	~HWResource ()

Static Public Attributes
static Class *	m_theClass

Static Public Attributes inherited from mitsuba::AbstractEmitter
static Class *	m_theClass

Static Public Attributes inherited from mitsuba::ConfigurableObject
static Class *	m_theClass

Static Public Attributes inherited from mitsuba::SerializableObject
static Class *	m_theClass

Static Public Attributes inherited from Object
static Class *	m_theClass
	Pointer to the object's class descriptor. More...

Protected Member Functions
	Emitter (const Properties &props)
	Construct a new emitter instance. More...

	Emitter (Stream stream, InstanceManager manager)
	Unserialize a emitter instance from a binary data stream. More...

virtual	~Emitter ()
	Virtual destructor. More...

Protected Member Functions inherited from mitsuba::AbstractEmitter
	AbstractEmitter (const Properties &props)
	Construct a new emitter instance. More...

	AbstractEmitter (Stream stream, InstanceManager manager)
	Unserialize a emitter instance from a binary data stream. More...

virtual	~AbstractEmitter ()
	Virtual destructor. More...

Protected Member Functions inherited from mitsuba::ConfigurableObject
virtual	~ConfigurableObject ()
	Virtual destructor. More...

	ConfigurableObject (const Properties &props)
	Construct a configurable object. More...

	ConfigurableObject (Stream stream, InstanceManager manager)
	Unserialize a configurable object. More...

Protected Member Functions inherited from mitsuba::SerializableObject
	SerializableObject ()
	Construct a serializable object. More...

virtual	~SerializableObject ()
	Virtual deconstructor. More...

Protected Member Functions inherited from Object
virtual	~Object ()
	Virtual private deconstructor. (Will only be called by ref) More...

Protected Attributes
Float	m_samplingWeight

Protected Attributes inherited from mitsuba::AbstractEmitter
ref< const AnimatedTransform >	m_worldTransform

ref< Medium >	m_medium

Shape *	m_shape

uint32_t	m_type

Protected Attributes inherited from mitsuba::ConfigurableObject
Properties	m_properties

Additional Inherited Members
Static Public Member Functions inherited from Object
static void	staticInitialization ()
	Initializes the built-in reference count debugger (if enabled) More...

static void	staticShutdown ()
	Free the memory taken by staticInitialization() More...

Detailed Description

Abstract radiance emitter interface.

This class provides an abstract interface to all emitter plugins in Mitsuba. It exposes functions for evaluating and sampling the emission profile, and it allows querying the probability density of the sampling method.

Member Enumeration Documentation

enum mitsuba::Emitter::EEmitterFlags

This list of flags is used to additionally characterize and classify the response functions of different types of sensors.

See Also: AbstractEmitter::EEmitterType

Enumerator
EEnvironmentEmitter	Is this an environment emitter, such as a HDRI map?

Constructor & Destructor Documentation

mitsuba::Emitter::Emitter ( const Properties & props )

protected

Construct a new emitter instance.

mitsuba::Emitter::Emitter	(	Stream *	stream,
		InstanceManager *	manager
	)

protected

Unserialize a emitter instance from a binary data stream.

virtual mitsuba::Emitter::~Emitter ( )

protectedvirtual

Virtual destructor.

Member Function Documentation

virtual Spectrum mitsuba::Emitter::eval	(	const Intersection &	its,
		const Vector &	d
	)		const

virtual

Return the radiant emittance for the given surface intersection.

This is function is used when an area light source has been hit by a ray in a path tracing-style integrator, and it subsequently needs to be queried for the emitted radiance along the negative ray direction.

It efficiently computes the product of evalPosition() and evalDirection() divided by the absolute cosine of the angle between d and its.shFrame.n.

This function is provided here as a fast convenience function for unidirectional rendering techniques. The default implementation throws an exception, which states that the method is not implemented.

Parameters

its	An intersect record that specfies the query position
d	A unit vector, which specifies the query direction

Returns: The radiant emittance

virtual Spectrum mitsuba::Emitter::evalEnvironment ( const RayDifferential & ray ) const

virtual

Return the radiant emittance from an environment emitter.

This is function is called by unidirectional rendering techniques (e.g. a path tracer) when no scene object has been intersected, and the scene has been determined to contain an environment emitter.

The default implementation throws an exception.

Parameters

ray	Specifies the ray direction that should be queried

virtual bool mitsuba::Emitter::fillDirectSamplingRecord	(	DirectSamplingRecord &	dRec,
		const Ray &	ray
	)		const

virtual

Fill out a data record that can be used to query the direct illumination sampling density of an environment emitter.

This is function is mainly called by unidirectional rendering techniques (e.g. a path tracer) when no scene object has been intersected, and the (hypothetical) sampling density of the environment emitter needs to be known by a multiple importance sampling technique.

The default implementation throws an exception.

Parameters

dRec	The direct illumination sampling record to be filled
ray	Specifies the ray direction that should be queried

Returns: true upon success

virtual ref<Bitmap> mitsuba::Emitter::getBitmap ( const Vector2i & sizeHint = Vector2i(-1,-1) ) const

virtual

Return a bitmap representation of the emitter.

Some types of light sources (projection lights, environment maps) are closely tied to an underlying bitmap data structure. This function can be used to return this information for various purposes.

When the class implementing this interface is a bitmap-backed texture, this function directly returns the underlying bitmap. When it is procedural, a bitmap version must first be generated. In this case, the parameter sizeHint is used to control the target size. The default value -1, -1 allows the implementation to choose a suitable size by itself.

Remarks: The default implementation throws an exception

virtual const Class* mitsuba::Emitter::getClass ( ) const

virtual

Retrieve this object's class.

Reimplemented from mitsuba::AbstractEmitter.

virtual Emitter* mitsuba::Emitter::getElement ( size_t index )

virtual

Return a sub-element of a compound emitter.

When expanding emitters, the scene will repeatedly call this function with increasing indices. Returning NULL indicates that no more are available.

Float mitsuba::Emitter::getSamplingWeight ( ) const

inline

Return the luminaire's sampling weight.

This is used by the luminaire importance sampling routines in Scene.

virtual bool mitsuba::Emitter::isCompound ( ) const

virtual

Is this a compound emitter consisting of several sub-objects?

bool mitsuba::Emitter::isEnvironmentEmitter ( ) const

inline

Is this an environment emitter? (e.g. an HDRI environment map?)

virtual Spectrum mitsuba::Emitter::sampleRay	(	Ray &	ray,
		const Point2 &	spatialSample,
		const Point2 &	directionalSample,
		Float	time
	)		const

virtual

Importance sample a ray according to the emission profile.

This function combines both steps of choosing a ray origin and direction value. It does not return any auxiliary sampling information and is mainly meant to be used by unidirectional rendering techniques.

Note that this function potentially uses a different sampling strategy compared to the sequence of running sampleArea() and sampleDirection(). The reason for this is that it may be possible to switch to a better technique when sampling both position and direction at the same time.

Parameters

ray	A ray data structure to be populated with a position and direction value
spatialSample	Denotes the sample that is used to choose the spatial component
directionalSample	Denotes the sample that is used to choose the directional component
time	Scene time value to be associated with the sample

Returns: An importance weight associated with the sampled ray. This accounts for the difference between the emission profile and the sampling density function.

virtual void mitsuba::Emitter::serialize	(	Stream *	stream,
		InstanceManager *	manager
	)		const

virtual

Serialize this emitter to a binary data stream.

Reimplemented from mitsuba::AbstractEmitter.

Member Data Documentation

Float mitsuba::Emitter::m_samplingWeight

protected

Class* mitsuba::Emitter::m_theClass

static

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

include/mitsuba/render/emitter.h

Public Types

Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation