a simple but quality lighting kit More...

#include <vtkLightKit.h>

Inheritance diagram for vtkLightKit:

Collaboration diagram for vtkLightKit:

Public Types
enum	LightKitType { TKeyLight, TFillLight, TBackLight, THeadLight }

enum	LightKitSubType { Warmth, Intensity, Elevation, Azimuth, KFRatio, KBRatio, KHRatio }

typedef vtkObject	Superclass

Public Types inherited from vtkObject
typedef vtkObjectBase	Superclass

Public Member Functions
virtual int	IsA (const char *type)

vtkLightKit *	NewInstance () const

void	PrintSelf (ostream &os, vtkIndent indent)

virtual void	SetFillLightWarmth (double)

virtual double	GetFillLightWarmth ()

virtual void	SetHeadLightWarmth (double)

virtual double	GetHeadLightWarmth ()

virtual void	SetBackLightWarmth (double)

virtual double	GetBackLightWarmth ()

void	SetKeyLightElevation (double x)

void	SetKeyLightAzimuth (double x)

virtual double *	GetKeyLightAngle ()

virtual void	GetKeyLightAngle (double data[2])

double	GetKeyLightElevation ()

double	GetKeyLightAzimuth ()

void	SetFillLightAngle (double elevation, double azimuth)

void	SetFillLightAngle (double angle[2])

void	SetFillLightElevation (double x)

void	SetFillLightAzimuth (double x)

virtual double *	GetFillLightAngle ()

virtual void	GetFillLightAngle (double data[2])

double	GetFillLightElevation ()

double	GetFillLightAzimuth ()

void	SetBackLightAngle (double elevation, double azimuth)

void	SetBackLightAngle (double angle[2])

void	SetBackLightElevation (double x)

void	SetBackLightAzimuth (double x)

virtual double *	GetBackLightAngle ()

virtual void	GetBackLightAngle (double data[2])

double	GetBackLightElevation ()

double	GetBackLightAzimuth ()

void	DeepCopy (vtkLightKit *kit)

void	Modified ()

void	Update ()


virtual void	SetKeyLightIntensity (double)

virtual double	GetKeyLightIntensity ()


virtual void	SetKeyToFillRatio (double)

virtual double	GetKeyToFillRatio ()


virtual void	SetKeyToHeadRatio (double)

virtual double	GetKeyToHeadRatio ()


virtual void	SetKeyToBackRatio (double)

virtual double	GetKeyToBackRatio ()


virtual void	SetKeyLightWarmth (double)

virtual double	GetKeyLightWarmth ()


virtual double *	GetKeyLightColor ()

virtual void	GetKeyLightColor (double data[3])

virtual double *	GetFillLightColor ()

virtual void	GetFillLightColor (double data[3])

virtual double *	GetHeadLightColor ()

virtual void	GetHeadLightColor (double data[3])

virtual double *	GetBackLightColor ()

virtual void	GetBackLightColor (double data[3])


virtual void	MaintainLuminanceOn ()

virtual void	MaintainLuminanceOff ()

virtual int	GetMaintainLuminance ()

virtual void	SetMaintainLuminance (int)


void	SetKeyLightAngle (double elevation, double azimuth)

void	SetKeyLightAngle (double angle[2])


void	AddLightsToRenderer (vtkRenderer *renderer)

void	RemoveLightsFromRenderer (vtkRenderer *renderer)

Public Member Functions inherited from vtkObject
vtkObject *	NewInstance () const

virtual void	DebugOn ()

virtual void	DebugOff ()

bool	GetDebug ()

void	SetDebug (bool debugFlag)

virtual unsigned long	GetMTime ()

unsigned long	AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)

unsigned long	AddObserver (const char event, vtkCommand , float priority=0.0f)

vtkCommand *	GetCommand (unsigned long tag)

void	RemoveObserver (vtkCommand *)

void	RemoveObservers (unsigned long event, vtkCommand *)

void	RemoveObservers (const char event, vtkCommand )

int	HasObserver (unsigned long event, vtkCommand *)

int	HasObserver (const char event, vtkCommand )

void	RemoveObserver (unsigned long tag)

void	RemoveObservers (unsigned long event)

void	RemoveObservers (const char *event)

void	RemoveAllObservers ()

int	HasObserver (unsigned long event)

int	HasObserver (const char *event)

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, bool(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)

int	InvokeEvent (unsigned long event, void *callData)

int	InvokeEvent (const char event, void callData)

int	InvokeEvent (unsigned long event)

int	InvokeEvent (const char *event)

Public Member Functions inherited from vtkObjectBase
const char *	GetClassName () const

virtual void	Delete ()

virtual void	FastDelete ()

void	Print (ostream &os)

virtual void	Register (vtkObjectBase *o)

virtual void	UnRegister (vtkObjectBase *o)

void	SetReferenceCount (int)

void	PrintRevisions (ostream &)

virtual void	PrintHeader (ostream &os, vtkIndent indent)

virtual void	PrintTrailer (ostream &os, vtkIndent indent)

int	GetReferenceCount ()

Static Public Member Functions
static vtkLightKit *	New ()

static int	IsTypeOf (const char *type)

static vtkLightKit *	SafeDownCast (vtkObjectBase *o)

static const char *	GetStringFromType (int type)

static const char *	GetStringFromSubType (int type)

static const char *	GetShortStringFromSubType (int subtype)

static LightKitSubType	GetSubType (LightKitType type, int i)

Static Public Member Functions inherited from vtkObject
static int	IsTypeOf (const char *type)

static vtkObject *	SafeDownCast (vtkObjectBase *o)

static vtkObject *	New ()

static void	BreakOnError ()

static void	SetGlobalWarningDisplay (int val)

static void	GlobalWarningDisplayOn ()

static void	GlobalWarningDisplayOff ()

static int	GetGlobalWarningDisplay ()

Static Public Member Functions inherited from vtkObjectBase
static int	IsTypeOf (const char *name)

static vtkObjectBase *	New ()

Protected Member Functions
virtual vtkObjectBase *	NewInstanceInternal () const

	vtkLightKit ()

	~vtkLightKit ()

void	WarmthToRGBI (double w, double rgb[3], double &i)

void	WarmthToRGB (double w, double rgb[3])

void	InitializeWarmthFunctions ()

double	WarmthToIntensity (double w)

Protected Member Functions inherited from vtkObject
	vtkObject ()

virtual	~vtkObject ()

virtual void	RegisterInternal (vtkObjectBase *, int check)

virtual void	UnRegisterInternal (vtkObjectBase *, int check)

void	InternalGrabFocus (vtkCommand mouseEvents, vtkCommand keypressEvents=NULL)

void	InternalReleaseFocus ()

Protected Member Functions inherited from vtkObjectBase
	vtkObjectBase ()

virtual	~vtkObjectBase ()

virtual void	CollectRevisions (ostream &)

virtual void	ReportReferences (vtkGarbageCollector *)

	vtkObjectBase (const vtkObjectBase &)

void	operator= (const vtkObjectBase &)

Protected Attributes
double	KeyLightIntensity

double	KeyToFillRatio

double	KeyToHeadRatio

double	KeyToBackRatio

vtkLight *	KeyLight

double	KeyLightWarmth

double	KeyLightAngle [2]

double	KeyLightColor [3]

vtkLight *	FillLight

double	FillLightWarmth

double	FillLightAngle [2]

double	FillLightColor [3]

double	BackLightWarmth

double	BackLightColor [3]

vtkLight *	BackLight0

vtkLight *	BackLight1

double	BackLightAngle [2]

vtkLight *	HeadLight

double	HeadLightWarmth

double	HeadLightColor [3]

int	MaintainLuminance

vtkPiecewiseFunction *	WarmthFunction [4]

Protected Attributes inherited from vtkObject
bool	Debug

vtkTimeStamp	MTime

vtkSubjectHelper *	SubjectHelper

Protected Attributes inherited from vtkObjectBase
vtkAtomicInt32	ReferenceCount

vtkWeakPointerBase **	WeakPointers

Detailed Description

a simple but quality lighting kit

vtkLightKit is designed to make general purpose lighting of vtk scenes simple, flexible, and attractive (or at least not horribly ugly without significant effort). Use a LightKit when you want more control over your lighting than you can get with the default vtk light, which is a headlight located at the camera. (HeadLights are very simple to use, but they don't show the shape of objects very well, don't give a good sense of "up" and "down", and don't evenly light the object.)

A LightKit consists of three lights, a key light, a fill light, and a headlight. The main light is the key light. It is usually positioned so that it appears like an overhead light (like the sun, or a ceiling light). It is generally positioned to shine down on the scene from about a 45 degree angle vertically and at least a little offset side to side. The key light usually at least about twice as bright as the total of all other lights in the scene to provide good modeling of object features.

The other lights in the kit (the fill light, headlight, and a pair of back lights) are weaker sources that provide extra illumination to fill in the spots that the key light misses. The fill light is usually positioned across from or opposite from the key light (though still on the same side of the object as the camera) in order to simulate diffuse reflections from other objects in the scene. The headlight, always located at the position of the camera, reduces the contrast between areas lit by the key and fill light. The two back lights, one on the left of the object as seen from the observer and one on the right, fill on the high-contrast areas behind the object. To enforce the relationship between the different lights, the intensity of the fill, back and headlights are set as a ratio to the key light brightness. Thus, the brightness of all the lights in the scene can be changed by changing the key light intensity.

All lights are directional lights (infinitely far away with no falloff). Lights move with the camera.

For simplicity, the position of lights in the LightKit can only be specified using angles: the elevation (latitude) and azimuth (longitude) of each light with respect to the camera, expressed in degrees. (Lights always shine on the camera's lookat point.) For example, a light at (elevation=0, azimuth=0) is located at the camera (a headlight). A light at (elevation=90, azimuth=0) is above the lookat point, shining down. Negative azimuth values move the lights clockwise as seen above, positive values counter-clockwise. So, a light at (elevation=45, azimuth=-20) is above and in front of the object and shining slightly from the left side.

vtkLightKit limits the colors that can be assigned to any light to those of incandescent sources such as light bulbs and sunlight. It defines a special color spectrum called "warmth" from which light colors can be chosen, where 0 is cold blue, 0.5 is neutral white, and 1 is deep sunset red. Colors close to 0.5 are "cool whites" and "warm whites," respectively.

Since colors far from white on the warmth scale appear less bright, key-to-fill and key-to-headlight ratios are skewed by key, fill, and headlight colors. If the flag MaintainLuminance is set, vtkLightKit will attempt to compensate for these perceptual differences by increasing the brightness of more saturated colors.

A LightKit is not explicitly part of the vtk pipeline. Rather, it is a composite object that controls the behavior of lights using a unified user interface. Every time a parameter of vtkLightKit is adjusted, the properties of its lights are modified.

Credits:: vtkLightKit was originally written and contributed to vtk by Michael Halle (mhall.nosp@m.e@bw.nosp@m.h.har.nosp@m.vard.nosp@m..edu) at the Surgical Planning Lab, Brigham and Women's Hospital.

Examples:: vtkLightKit (Examples)

Tests:: vtkLightKit (Tests)

Definition at line 107 of file vtkLightKit.h.

Member Typedef Documentation

typedef vtkObject vtkLightKit::Superclass

Definition at line 111 of file vtkLightKit.h.

Member Enumeration Documentation

enum vtkLightKit::LightKitType

Enumerator
TKeyLight
TFillLight
TBackLight
THeadLight

Definition at line 115 of file vtkLightKit.h.

enum vtkLightKit::LightKitSubType

Enumerator
Warmth
Intensity
Elevation
Azimuth
KFRatio
KBRatio
KHRatio

Definition at line 122 of file vtkLightKit.h.

Constructor & Destructor Documentation

vtkLightKit::vtkLightKit ( )

protected

vtkLightKit::~vtkLightKit ( )

protected

Member Function Documentation

static vtkLightKit* vtkLightKit::New ( )

static

static int vtkLightKit::IsTypeOf ( const char * type )

static

virtual int vtkLightKit::IsA ( const char * name )

virtual

Return 1 if this class is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.

Reimplemented from vtkObject.

static vtkLightKit* vtkLightKit::SafeDownCast ( vtkObjectBase * o )

static

virtual vtkObjectBase* vtkLightKit::NewInstanceInternal ( ) const

protectedvirtual

Reimplemented from vtkObject.

vtkLightKit* vtkLightKit::NewInstance ( ) const

void vtkLightKit::PrintSelf	(	ostream &	os,
		vtkIndent	indent
	)

virtual

Methods invoked by print to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from vtkObject.

virtual void vtkLightKit::SetKeyLightIntensity ( double )

virtual

Set/Get the intensity of the key light. The key light is the brightest light in the scene. The intensities of the other two lights are ratios of the key light's intensity.

virtual double vtkLightKit::GetKeyLightIntensity ( )

virtual

Set/Get the intensity of the key light. The key light is the brightest light in the scene. The intensities of the other two lights are ratios of the key light's intensity.

virtual void vtkLightKit::SetKeyToFillRatio ( double )

virtual

Set/Get the key-to-fill ratio. This ratio controls how bright the fill light is compared to the key light: larger values correspond to a dimmer fill light. The purpose of the fill light is to light parts of the object not lit by the key light, while still maintaining constrast. This type of lighting may correspond to indirect illumination from the key light, bounced off a wall, floor, or other object. The fill light should never be brighter than the key light: a good range for the key-to-fill ratio is between 2 and 10.

virtual double vtkLightKit::GetKeyToFillRatio ( )

virtual

Set/Get the key-to-fill ratio. This ratio controls how bright the fill light is compared to the key light: larger values correspond to a dimmer fill light. The purpose of the fill light is to light parts of the object not lit by the key light, while still maintaining constrast. This type of lighting may correspond to indirect illumination from the key light, bounced off a wall, floor, or other object. The fill light should never be brighter than the key light: a good range for the key-to-fill ratio is between 2 and 10.

virtual void vtkLightKit::SetKeyToHeadRatio ( double )

virtual

Set/Get the key-to-headlight ratio. Similar to the key-to-fill ratio, this ratio controls how bright the headlight light is compared to the key light: larger values correspond to a dimmer headlight light. The headlight is special kind of fill light, lighting only the parts of the object that the camera can see. As such, a headlight tends to reduce the contrast of a scene. It can be used to fill in "shadows" of the object missed by the key and fill lights. The headlight should always be significantly dimmer than the key light: ratios of 2 to 15 are typical.

virtual double vtkLightKit::GetKeyToHeadRatio ( )

virtual

Set/Get the key-to-headlight ratio. Similar to the key-to-fill ratio, this ratio controls how bright the headlight light is compared to the key light: larger values correspond to a dimmer headlight light. The headlight is special kind of fill light, lighting only the parts of the object that the camera can see. As such, a headlight tends to reduce the contrast of a scene. It can be used to fill in "shadows" of the object missed by the key and fill lights. The headlight should always be significantly dimmer than the key light: ratios of 2 to 15 are typical.

virtual void vtkLightKit::SetKeyToBackRatio ( double )

virtual

Set/Get the key-to-back light ratio. This ratio controls how bright the back lights are compared to the key light: larger values correspond to dimmer back lights. The back lights fill in the remaining high-contrast regions behind the object. Values between 2 and 10 are good.

virtual double vtkLightKit::GetKeyToBackRatio ( )

virtual

Set/Get the key-to-back light ratio. This ratio controls how bright the back lights are compared to the key light: larger values correspond to dimmer back lights. The back lights fill in the remaining high-contrast regions behind the object. Values between 2 and 10 are good.

virtual void vtkLightKit::SetKeyLightWarmth ( double )

virtual

Set the warmth of each the lights. Warmth is a parameter that varies from 0 to 1, where 0 is "cold" (looks icy or lit by a very blue sky), 1 is "warm" (the red of a very red sunset, or the embers of a campfire), and 0.5 is a neutral white. The warmth scale is non-linear. Warmth values close to 0.5 are subtly "warmer" or "cooler," much like a warmer tungsten incandescent bulb, a cooler halogen, or daylight (cooler still). Moving further away from 0.5, colors become more quickly varying towards blues and reds. With regards to aesthetics, extremes of warmth should be used sparingly.

virtual double vtkLightKit::GetKeyLightWarmth ( )

virtual

Set the warmth of each the lights. Warmth is a parameter that varies from 0 to 1, where 0 is "cold" (looks icy or lit by a very blue sky), 1 is "warm" (the red of a very red sunset, or the embers of a campfire), and 0.5 is a neutral white. The warmth scale is non-linear. Warmth values close to 0.5 are subtly "warmer" or "cooler," much like a warmer tungsten incandescent bulb, a cooler halogen, or daylight (cooler still). Moving further away from 0.5, colors become more quickly varying towards blues and reds. With regards to aesthetics, extremes of warmth should be used sparingly.

virtual void vtkLightKit::SetFillLightWarmth ( double )

virtual

virtual double vtkLightKit::GetFillLightWarmth ( )

virtual

virtual void vtkLightKit::SetHeadLightWarmth ( double )

virtual

virtual double vtkLightKit::GetHeadLightWarmth ( )

virtual

virtual void vtkLightKit::SetBackLightWarmth ( double )

virtual

virtual double vtkLightKit::GetBackLightWarmth ( )

virtual

virtual double* vtkLightKit::GetKeyLightColor ( )

virtual