PySide6.QtQuick3D.QQuick3DInstancing

class QQuick3DInstancing

Base class for defining instance tables. More…

Synopsis

Properties

• depthSortingEnabledᅟ

• hasTransparencyᅟ

• instanceCountOverrideᅟ

Methods

• def __init__()

• def depthSortingEnabled()

• def hasTransparency()

• def instanceBuffer()

• def instanceColor()

• def instanceCountOverride()

• def instanceCustomData()

• def instancePosition()

• def instanceRotation()

• def instanceScale()

• def markDirty()

Virtual methods

• def getInstanceBuffer()

Slots

• def setDepthSortingEnabled()

• def setHasTransparency()

• def setInstanceCountOverride()

Signals

• def depthSortingEnabledChanged()

• def hasTransparencyChanged()

• def instanceCountOverrideChanged()

• def instanceNodeDirty()

• def instanceTableChanged()

Static functions

• def calculateTableEntry()

• def calculateTableEntryFromQuaternion()

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description

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() .

Note

Properties can be used directly when from __feature__ import true_property is used or via accessor functions otherwise.

property depthSortingEnabledᅟ: 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.

Note

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

Note

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

Access functions:

• depthSortingEnabled()

• setDepthSortingEnabled()

• Signal depthSortingEnabledChanged()

property hasTransparencyᅟ: 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 , or an opacity less than one, the alpha value from the table will be used regardless.

Note

Enabling alpha blending may cause rendering issues when instances overlap. See the alpha blending and instancing documentation for details.

Access functions:

• hasTransparency()

• setHasTransparency()

• Signal hasTransparencyChanged()

property instanceCountOverrideᅟ: 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.

Access functions:

• instanceCountOverride()

• setInstanceCountOverride()

• Signal instanceCountOverrideChanged()

__init__([parent=None])

Parameters:

parent – QQuick3DObject

static calculateTableEntry(position, scale, eulerRotation, color[, customData={}])

Parameters:

• position – QVector3D

• scale – QVector3D

• eulerRotation – QVector3D

• color – QColor

• customData – QVector4D

Return type:

InstanceTableEntry

Converts the 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));

See also

calculateTableEntryFromQuaternion

static calculateTableEntryFromQuaternion(position, scale, rotation, color[, customData={}])

Parameters:

• position – QVector3D

• scale – QVector3D

• rotation – QQuaternion

• color – QColor

• customData – QVector4D

Return type:

InstanceTableEntry

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

This is the same as calculateTableEntry() , except for using a quaternion to specify the rotation.

depthSortingEnabled()

Return type:

bool

See also

setDepthSortingEnabled()

Getter of property depthSortingEnabledᅟ .

depthSortingEnabledChanged()

Notification signal of property depthSortingEnabledᅟ .

abstract getInstanceBuffer(instanceCount)

Parameters:

instanceCount – int

Return type:

QByteArray

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() .

hasTransparency()

Return type:

bool

See also

setHasTransparency()

Getter of property hasTransparencyᅟ .

hasTransparencyChanged()

Notification signal of property hasTransparencyᅟ .

instanceBuffer(instanceCount)

Parameters:

instanceCount – int

Return type:

QByteArray

instanceColor(index)

Parameters:

index – int

Return type:

QColor

instanceCountOverride()

Return type:

int

See also

setInstanceCountOverride()

Getter of property instanceCountOverrideᅟ .

instanceCountOverrideChanged()

Notification signal of property instanceCountOverrideᅟ .

instanceCustomData(index)

Parameters:

index – int

Return type:

QVector4D

instanceNodeDirty()

instancePosition(index)

Parameters:

index – int

Return type:

QVector3D

instanceRotation(index)

Parameters:

index – int

Return type:

QQuaternion

instanceScale(index)

Parameters:

index – int

Return type:

QVector3D

instanceTableChanged()

markDirty()

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

See also

getInstanceBuffer instanceCountOverride

setDepthSortingEnabled(enabled)

Parameters:

enabled – bool

See also

depthSortingEnabled()

Setter of property depthSortingEnabledᅟ .

setHasTransparency(hasTransparency)

Parameters:

hasTransparency – bool

See also

hasTransparency()

Setter of property hasTransparencyᅟ .

setInstanceCountOverride(instanceCountOverride)

Parameters:

instanceCountOverride – int

See also

instanceCountOverride()

Setter of property instanceCountOverrideᅟ .