内容

• 特性
• 公共函数
• 公共槽
• 信号
• 保护函数
• 静态保护成员
• 详细描述

QQuick3DInstancing Class

Base class for defining instance tables. 更多...

头：	#include <QQuick3DInstancing>
Since:	Qt 6.2
实例化：	Instancing
继承：	QQuick3DObject

• 所有成员列表，包括继承成员

特性

• depthSortingEnabled : bool
• hasTransparency : bool
• instanceCountOverride : int

公共函数

bool	depthSortingEnabled () const
bool	hasTransparency () const
int	instanceCountOverride () const

公共槽

void	setDepthSortingEnabled (bool enabled )
void	setHasTransparency (bool hasTransparency )
void	setInstanceCountOverride (int instanceCountOverride )

信号

void	depthSortingEnabledChanged ()
void	hasTransparencyChanged ()
void	instanceCountOverrideChanged ()

保护函数

virtual QByteArray	getInstanceBuffer (int * instanceCount ) = 0
void	markDirty ()

静态保护成员

QQuick3DInstancing::InstanceTableEntry	calculateTableEntry (const QVector3D & position , const QVector3D & scale , const QVector3D & eulerRotation , const QColor & color , const QVector4D & customData = {})
QQuick3DInstancing::InstanceTableEntry	calculateTableEntryFromQuaternion (const QVector3D & position , const QVector3D & scale , const QQuaternion & rotation , const QColor & color , const QVector4D & customData = {})

详细描述

The QQuick3DInstancing class can be inherited to specify a custom instance table for a Model in the Qt Quick 3D scene.

This class is abstract: To use it, create a subclass and implement getInstanceBuffer ().

特性文档编制

depthSortingEnabled : bool

Holds the depth sorting enabled value for the instance table. When enabled, instances are sorted and rendered from the furthest instance from the camera to the nearest i.e. back-to-front. If disabled, which is the default, instances are rendered in the order they are specified in the instance table.

注意： The instances are only sorted against each other. Instances are not sorted against other objects in the scene.

注意： The sorting increases the frame preparation time especially with large instance counts.

访问函数：

bool	depthSortingEnabled () const
void	setDepthSortingEnabled (bool enabled )

通知程序信号：

void	depthSortingEnabledChanged ()

hasTransparency : bool

Set this property to true if the instancing table contains alpha values that should be used when rendering the model. This property only makes a difference if the model is opaque: If the model has a transparent material ，或 opacity less than one, the alpha value from the table will be used regardless.

注意： Enabling alpha blending may cause rendering issues when instances overlap. See the alpha blending and instancing 文档编制了解细节。

访问函数：

bool	hasTransparency () const
void	setHasTransparency (bool hasTransparency )

通知程序信号：

void	hasTransparencyChanged ()

instanceCountOverride : int

Set this property to limit the number of instances without regenerating or re-uploading the instance table. This allows very inexpensive animation of the number of instances rendered.

访问函数：

int	instanceCountOverride () const
void	setInstanceCountOverride (int instanceCountOverride )

通知程序信号：

void	instanceCountOverrideChanged ()

成员函数文档编制

[static protected] QQuick3DInstancing::InstanceTableEntry QQuick3DInstancing:: calculateTableEntry (const QVector3D & position , const QVector3D & scale , const QVector3D & eulerRotation , const QColor & color , const QVector4D & customData = {})

转换 position scale eulerRotation color and customData to the instance table format expected by the standard vertex shaders. Typical pattern:

QByteArray MyInstanceTable::getInstanceBuffer(int *instanceCount)
{
    QByteArray instanceData;
    ...
    auto entry = calculateTableEntry({xPos, yPos, zPos}, {xScale, yScale, zScale}, {xRot, yRot, zRot}, color, {});
    instanceData.append(reinterpret_cast<const char *>(&entry), sizeof(entry));
					

另请参阅 calculateTableEntryFromQuaternion .

[static protected] QQuick3DInstancing::InstanceTableEntry QQuick3DInstancing:: calculateTableEntryFromQuaternion (const QVector3D & position , const QVector3D & scale , const QQuaternion & rotation , const QColor & color , const QVector4D & customData = {})

转换 position scale rotation color and customData to the instance table format expected by the standard vertex shaders.

这如同 calculateTableEntry (), except for using a quaternion to specify the rotation.

[pure virtual protected] QByteArray QQuick3DInstancing:: getInstanceBuffer ( int * instanceCount )

Implement this function to return the contents of the instance table. The number of instances should be returned in instanceCount . The subclass is responsible for caching the result if necessary. If the instance table changes, the subclass should call markDirty ().

[protected] void QQuick3DInstancing:: markDirty ()

Mark that the instance data has changed and must be uploaded again.

另请参阅 getInstanceBuffer and instanceCountOverride .