V3d_PositionalLight Class Reference

Creation and modification of an isolated (positional) light source. It is also defined by the color and two attenuation factors ConstAttentuation() and LinearAttentuation(). The resulting attenuation factor determining the illumination of a surface depends on the following formula: More...

#include <V3d_PositionalLight.hxx>

Inheritance diagram for V3d_PositionalLight:

Public Member Functions
	V3d_PositionalLight (const gp_Pnt &thePos, const Quantity_Color &theColor=Quantity_NOC_WHITE)
	Creates an isolated light source in the viewer with default attenuation factors (1.0, 0.0).
const gp_Pnt &	Position () const
	Returns location of positional/spot light; (0, 0, 0) by default.
void	Position (double &theX, double &theY, double &theZ) const
	Returns location of positional/spot light.
void	SetPosition (const gp_Pnt &thePosition)
	Setup location of positional/spot light.
void	SetPosition (double theX, double theY, double theZ)
	Setup location of positional/spot light.
Public Member Functions inherited from Graphic3d_CLight
	Graphic3d_CLight (Graphic3d_TypeOfLightSource theType)
	Empty constructor, which should be followed by light source properties configuration.
void	CopyFrom (const occ::handle< Graphic3d_CLight > &theLight)
	Copy parameters from another light source excluding source type.
Graphic3d_TypeOfLightSource	Type () const
	Returns the Type of the Light, cannot be changed after object construction.
const TCollection_AsciiString &	Name () const
	Returns light source name; empty string by default.
void	SetName (const TCollection_AsciiString &theName)
	Sets light source name.
const Quantity_Color &	Color () const
	Returns the color of the light source; WHITE by default.
void	SetColor (const Quantity_Color &theColor)
	Defines the color of a light source by giving the basic color.
bool	IsEnabled () const
	Check that the light source is turned on; TRUE by default. This flag affects all occurrences of light sources, where it was registered and activated; so that it is possible defining an active light in View which is actually in disabled state.
void	SetEnabled (bool theIsOn)
	Change enabled state of the light state. This call does not remove or deactivate light source in Views/Viewers; instead it turns it OFF so that it just have no effect.
bool	ToCastShadows () const
	Return TRUE if shadow casting is enabled; FALSE by default. Has no effect in Ray-Tracing rendering mode.
void	SetCastShadows (bool theToCast)
	Enable/disable shadow casting.
bool	IsHeadlight () const
	Returns true if the light is a headlight; FALSE by default. Headlight flag means that light position/direction are defined not in a World coordinate system, but relative to the camera orientation.
bool	Headlight () const
	Alias for IsHeadlight().
void	SetHeadlight (bool theValue)
	Setup headlight flag.
const gp_Pnt &	Position () const
	Returns location of positional/spot light; (0, 0, 0) by default.
void	SetPosition (const gp_Pnt &thePosition)
	Setup location of positional/spot light.
void	Position (double &theX, double &theY, double &theZ) const
	Returns location of positional/spot light.
void	SetPosition (double theX, double theY, double theZ)
	Setup location of positional/spot light.
float	ConstAttenuation () const
	Returns constant attenuation factor of positional/spot light source; 1.0f by default. Distance attenuation factors of reducing positional/spot light intensity depending on the distance from its position:
float	LinearAttenuation () const
	Returns linear attenuation factor of positional/spot light source; 0.0 by default. Distance attenuation factors of reducing positional/spot light intensity depending on the distance from its position:
void	Attenuation (double &theConstAttenuation, double &theLinearAttenuation) const
	Returns the attenuation factors.
void	SetAttenuation (float theConstAttenuation, float theLinearAttenuation)
	Defines the coefficients of attenuation; values should be >= 0.0 and their summ should not be equal to 0.
gp_Dir	Direction () const
	Returns direction of directional/spot light.
void	SetDirection (const gp_Dir &theDir)
	Sets direction of directional/spot light.
void	Direction (double &theVx, double &theVy, double &theVz) const
	Returns the theVx, theVy, theVz direction of the light source.
void	SetDirection (double theVx, double theVy, double theVz)
	Sets direction of directional/spot light.
const gp_Pnt &	DisplayPosition () const
	Returns location of positional/spot/directional light, which is the same as returned by Position().
void	SetDisplayPosition (const gp_Pnt &thePosition)
	Setup location of positional/spot/directional light, which is the same as SetPosition() but allows directional light source (technically having no position, but this point can be used for displaying light source presentation).
float	Angle () const
	Returns an angle in radians of the cone created by the spot; 30 degrees by default.
void	SetAngle (float theAngle)
	Angle in radians of the cone created by the spot, should be within range (0.0, M_PI).
float	Concentration () const
	Returns intensity distribution of the spot light, within [0.0, 1.0] range; 1.0 by default. This coefficient should be converted into spotlight exponent within [0.0, 128.0] range:
void	SetConcentration (float theConcentration)
	Defines the coefficient of concentration; value should be within range [0.0, 1.0].
float	Intensity () const
	Returns the intensity of light source; 1.0 by default.
void	SetIntensity (float theValue)
	Modifies the intensity of light source, which should be > 0.0.
float	Smoothness () const
	Returns the smoothness of light source (either smoothing angle for directional light or smoothing radius in case of positional light); 0.0 by default.
void	SetSmoothRadius (float theValue)
	Modifies the smoothing radius of positional/spot light; should be >= 0.0.
void	SetSmoothAngle (float theValue)
	Modifies the smoothing angle (in radians) of directional light source; should be within range [0.0, M_PI/2].
bool	HasRange () const
	Returns TRUE if maximum distance of point light source is defined.
float	Range () const
	Returns maximum distance on which point light source affects to objects and is considered during illumination calculations. 0.0 means disabling range considering at all without any distance limits. Has sense only for point light sources (positional and spot).
void	SetRange (float theValue)
	Modifies maximum distance on which point light source affects to objects and is considered during illumination calculations. Positional and spot lights are only point light sources. 0.0 means disabling range considering at all without any distance limits.
const TCollection_AsciiString &	GetId () const
const NCollection_Vec4< float > &	PackedParams () const
	Packed light parameters.
const NCollection_Vec4< float > &	PackedColor () const
	Returns the color of the light source with dummy Alpha component, which should be ignored.
const NCollection_Vec4< float > &	PackedDirectionRange () const
	Returns direction of directional/spot light and range for positional/spot light in alpha channel.
NCollection_Vec3< float >	PackedDirection () const
	Returns direction of directional/spot light.
size_t	Revision () const
void	DumpJson (Standard_OStream &theOStream, int theDepth=-1) const
	Dumps the content of me into the stream.
Public Member Functions inherited from Standard_Transient
	Standard_Transient ()
	Empty constructor.
	Standard_Transient (const Standard_Transient &)
	Copy constructor – does nothing.
Standard_Transient &	operator= (const Standard_Transient &)
	Assignment operator, needed to avoid copying reference counter.
virtual	~Standard_Transient ()=default
	Destructor must be virtual.
virtual const opencascade::handle< Standard_Type > &	DynamicType () const
	Returns a type descriptor about this object.
bool	IsInstance (const opencascade::handle< Standard_Type > &theType) const
	Returns a true value if this is an instance of Type.
bool	IsInstance (const char *const theTypeName) const
	Returns a true value if this is an instance of TypeName.
bool	IsKind (const opencascade::handle< Standard_Type > &theType) const
	Returns true if this is an instance of Type or an instance of any class that inherits from Type. Note that multiple inheritance is not supported by OCCT RTTI mechanism.
bool	IsKind (const char *const theTypeName) const
	Returns true if this is an instance of TypeName or an instance of any class that inherits from TypeName. Note that multiple inheritance is not supported by OCCT RTTI mechanism.
Standard_Transient *	This () const
	Returns non-const pointer to this object (like const_cast). For protection against creating handle to objects allocated in stack or call from constructor, it will raise exception Standard_ProgramError if reference counter is zero.
int	GetRefCount () const noexcept
	Get the reference counter of this object.
void	IncrementRefCounter () noexcept
	Increments the reference counter of this object. Uses relaxed memory ordering since incrementing only requires atomicity, not synchronization with other memory operations.
int	DecrementRefCounter () noexcept
	Decrements the reference counter of this object; returns the decremented value. Uses release ordering for the decrement to ensure all writes to the object are visible before the count reaches zero. An acquire fence is added only when the count reaches zero, ensuring proper synchronization before deletion. This is more efficient than using acq_rel for every decrement.
virtual void	Delete () const
	Memory deallocator for transient classes.

Additional Inherited Members
typedef void	base_type
	Returns a type descriptor about this object.
static constexpr const char *	get_type_name ()
	Returns a type descriptor about this object.
static const opencascade::handle< Standard_Type > &	get_type_descriptor ()
	Returns type descriptor of Standard_Transient class.
Protected Member Functions inherited from V3d_PositionLight
	V3d_PositionLight (Graphic3d_TypeOfLightSource theType)
	Protected constructor.
const gp_Pnt &	Position () const
	Returns location of positional/spot light; (0, 0, 0) by default.
void	Position (double &theX, double &theY, double &theZ) const
	Returns location of positional/spot light.
void	SetPosition (const gp_Pnt &thePosition)
	Setup location of positional/spot light.
void	SetPosition (double theX, double theY, double theZ)
	Setup location of positional/spot light.
TCollection_AsciiString	myId
	resource id
TCollection_AsciiString	myName
	user given name
gp_Pnt	myPosition
	light position
Quantity_ColorRGBA	myColor
	light color
NCollection_Vec4< float >	myDirection
	direction of directional/spot light
NCollection_Vec4< float >	myParams
	packed light parameters
float	mySmoothness
	radius for point light or cone angle for directional light
float	myIntensity
	intensity multiplier for light
const Graphic3d_TypeOfLightSource	myType
	Graphic3d_TypeOfLightSource enumeration.
size_t	myRevision
	modification counter
bool	myIsHeadlight
	flag to mark head light
bool	myIsEnabled
	enabled state
bool	myToCastShadows
	casting shadows is requested

Detailed Description

Creation and modification of an isolated (positional) light source. It is also defined by the color and two attenuation factors ConstAttentuation() and LinearAttentuation(). The resulting attenuation factor determining the illumination of a surface depends on the following formula:

F = 1 / (ConstAttenuation() + LinearAttenuation() * Distance)

Where Distance is the distance of the isolated source from the surface.

Constructor & Destructor Documentation

V3d_PositionalLight()

V3d_PositionalLight::V3d_PositionalLight	(	const gp_Pnt &	thePos,
		const Quantity_Color &	theColor = Quantity_NOC_WHITE )

Creates an isolated light source in the viewer with default attenuation factors (1.0, 0.0).

Member Function Documentation

Position() [1/2]

const gp_Pnt & Graphic3d_CLight::Position ( ) const

inline

Returns location of positional/spot light; (0, 0, 0) by default.

Position() [2/2]

void Graphic3d_CLight::Position ( double & theX, double & theY, double & theZ ) const

inline

Returns location of positional/spot light.

SetPosition() [1/2]

void Graphic3d_CLight::SetPosition

(

const gp_Pnt &

thePosition

)

Setup location of positional/spot light.

SetPosition() [2/2]

void Graphic3d_CLight::SetPosition ( double theX, double theY, double theZ )

inline

Setup location of positional/spot light.

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

• V3d_PositionalLight.hxx