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QPointLight Class

class Qt3DRender::QPointLight

Encapsulate a Point Light object in a Qt 3D scene. More...

Header: #include <QPointLight>
qmake: QT += 3drender
Since: Qt 5.5
Instantiated By: PointLight
Inherits: Qt3DRender::QAbstractLight

This class was introduced in Qt 5.5.

Properties

Public Functions

QPointLight(Qt3DCore::QNode *parent = nullptr)
float constantAttenuation() const
float linearAttenuation() const
float quadraticAttenuation() const

Public Slots

void setConstantAttenuation(float value)
void setLinearAttenuation(float value)
void setQuadraticAttenuation(float value)

Signals

void constantAttenuationChanged(float constantAttenuation)
void linearAttenuationChanged(float linearAttenuation)
void quadraticAttenuationChanged(float quadraticAttenuation)

Detailed Description

A point light is a light source that emits light in all directions, from a single point. Conceptually, this is similar to light given off by a standard light bulb.

A point light uses three attenuation factors to describe how the intensity of the light decreases over distance. These factors are designed to be used together in calcuating total attenuation. For the materials in Qt3D Extras the following formula is used, where distance is the distance from the light to the surface being rendered:

totalAttenuation = 1.0 / (constantAttenuation + (linearAttenuation * distance) + (quadraticAttenuation * distance * distance));

Custom materials may choose to interpret these factors differently.

Property Documentation

constantAttenuation : float

Specifies the constant attenuation of the point light.

Note: The exact meaning and use of this property is up to the material implementation.

Access functions:

float constantAttenuation() const
void setConstantAttenuation(float value)

Notifier signal:

void constantAttenuationChanged(float constantAttenuation)

linearAttenuation : float

Specifies the linear attenuation of the point light.

Note: The exact meaning and use of this property is up to the material implementation.

Access functions:

float linearAttenuation() const
void setLinearAttenuation(float value)

Notifier signal:

void linearAttenuationChanged(float linearAttenuation)

quadraticAttenuation : float

Specifies the quadratic attenuation of the point light.

Note: The exact meaning and use of this property is up to the material implementation.

Access functions:

float quadraticAttenuation() const
void setQuadraticAttenuation(float value)

Notifier signal:

void quadraticAttenuationChanged(float quadraticAttenuation)

Member Function Documentation

QPointLight::QPointLight(Qt3DCore::QNode *parent = nullptr)

Constructs a new QPointLight with the specified parent.

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