内容

• 特性
• 公共函数
• 公共槽
• 信号
• 详细描述

QSpotLight Class

class Qt3DRender ::QSpotLight

Encapsulate a Spot Light object in a Qt 3D scene. 更多...

头：	#include <QSpotLight>
qmake:	QT += 3drender
Since:	Qt 5.5
实例化：	SpotLight
继承：	Qt3DRender::QAbstractLight

该类在 Qt 5.5 引入。

• 所有成员列表，包括继承成员

特性

constantAttenuation : float cutOffAngle : float linearAttenuation : float

localDirection : QVector3D quadraticAttenuation : float

公共函数

	QSpotLight (Qt3DCore::QNode * parent = nullptr)
float	constantAttenuation () const
float	cutOffAngle () const
float	linearAttenuation () const
QVector3D	localDirection () const
float	quadraticAttenuation () const

公共槽

void	setConstantAttenuation (float value )
void	setCutOffAngle (float cutOffAngle )
void	setLinearAttenuation (float value )
void	setLocalDirection (const QVector3D & localDirection )
void	setQuadraticAttenuation (float value )

信号

void	constantAttenuationChanged (float constantAttenuation )
void	cutOffAngleChanged (float cutOffAngle )
void	linearAttenuationChanged (float linearAttenuation )
void	localDirectionChanged (const QVector3D & localDirection )
void	quadraticAttenuationChanged (float quadraticAttenuation )

详细描述

A spotlight is a light source that emits a cone of light in a particular direction.

A spotlight 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.

特性文档编制

constantAttenuation : float

Specifies the constant attenuation of the spot light.

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

访问函数：

float	constantAttenuation () const
void	setConstantAttenuation (float value )

通知程序信号：

void	constantAttenuationChanged (float constantAttenuation )

cutOffAngle : float

Specifies the cut off angle of the spot light.

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

访问函数：

float	cutOffAngle () const
void	setCutOffAngle (float cutOffAngle )

通知程序信号：

void	cutOffAngleChanged (float cutOffAngle )

linearAttenuation : float

Specifies the linear attenuation of the spot light.

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

访问函数：

float	linearAttenuation () const
void	setLinearAttenuation (float value )

通知程序信号：

void	linearAttenuationChanged (float linearAttenuation )

localDirection : QVector3D

Specifies the local direction of the spot light.

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

访问函数：

QVector3D	localDirection () const
void	setLocalDirection (const QVector3D & localDirection )

通知程序信号：

void	localDirectionChanged (const QVector3D & localDirection )

quadraticAttenuation : float

Specifies the quadratic attenuation of the spot light.

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

访问函数：

float	quadraticAttenuation () const
void	setQuadraticAttenuation (float value )

通知程序信号：

void	quadraticAttenuationChanged (float quadraticAttenuation )

成员函数文档编制

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

Constructs a new QSpotLight with the specified parent .