Qt3DRender.QLevelOfDetail ¶

概要 ¶

详细描述 ¶

QLevelOfDetail can be used to control the representation of an entity based on distance from the observer or size on the screen.

In order to improve rendering performance, objects that are very small can be rendered using far fewer details, in geometry or texture.

The component is controlled by specifying thresholds of values which are interpreted as either distances from the camera or screen size.

As the point of view changes, the currentIndex property will change to reflect matching value in the range array.

currentIndex property can then be used, for example, to enable or disable entities, change material, etc.

LevelOfDetail component is not shareable between multiple entities .

 #include <Qt3DCore/QEntity>
 #include <Qt3DRender/QGeometryRenderer>
 #include <Qt3DRender/QLevelOfDetail>
// Scene
Qt3DCore::QEntity *rootEntity = new Qt3DCore::Qt3DCore::QEntity;
Qt3DCore::QEntity *renderableEntity = new Qt3DCore::QEntity(rootEntity);
Qt3DRender::QGeometryRenderer *geometryRenderer = new Qt3DCore::QGeometryRenderer(renderableEntity);
renderableEntity->addComponent(geometryRenderer);
Qt3DRender::QLevelOfDetail* lod = new Qt3Render::QLevelOfDetail(renderableEntity);
QVector<qreal> thresholds = {20, 35, 50, 65};
lod->setThresholds(thresholds);
lod->setCamera(mainCamera);
renderableEntity->addComponent(lod);
// connect to QLevelOfDetail::currentIndexChanged to toggle rendering
...
											

class PySide2.Qt3DRender.Qt3DRender. QLevelOfDetail ( [ parent=None ] ) ¶

param parent

QNode

构造新 QLevelOfDetail with the specified parent .

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. ThresholdType ¶

Specifies how the values in the thresholds are interpreted

常量	描述
Qt3DRender.QLevelOfDetail.DistanceToCameraThreshold	Distance from the entity to the selected camera
Qt3DRender.QLevelOfDetail.ProjectedScreenPixelSizeThreshold	Size of the entity when projected on the screen as seen from the selected camera, expressed in number of pixels on the side of the bounding square in screen space.

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. camera ( ) ¶

返回类型

QCamera

另请参阅

setCamera()

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. cameraChanged ( camera ) ¶

参数

camera – QCamera

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. createBoundingSphere ( center , radius ) ¶

参数

• center – QVector3D

• radius – float

返回类型

QLevelOfDetailBoundingSphere

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. currentIndex ( ) ¶

返回类型

int

另请参阅

setCurrentIndex()

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. currentIndexChanged ( currentIndex ) ¶

参数

currentIndex – int

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. setCamera ( camera ) ¶

参数

camera – QCamera

设置 camera relative to which distance and size are computed.

另请参阅

camera()

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. setCurrentIndex ( currentIndex ) ¶

参数

currentIndex – int

设置 currentIndex .

注意

This should not normally be set by the user.

However, if the component is disabled, then changing the current index is a simple way of switching between multiple representations.

另请参阅

currentIndex()

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. setThresholdType ( thresholdType ) ¶

参数

thresholdType – ThresholdType

Sets the way thresholds values are interpreted with parameter thresholdType

另请参阅

thresholdType() ThresholdType

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. setThresholds ( thresholds ) ¶

参数

thresholds –

Sets the range values in thresholds .

另请参阅

thresholds() thresholdType

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. setVolumeOverride ( volumeOverride ) ¶

参数

volumeOverride – QLevelOfDetailBoundingSphere

另请参阅

volumeOverride()

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. thresholdType ( ) ¶

返回类型

ThresholdType

另请参阅

setThresholdType()

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. thresholdTypeChanged ( thresholdType ) ¶

参数

thresholdType – ThresholdType

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. thresholds ( ) ¶

返回类型

另请参阅

setThresholds()

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. thresholdsChanged ( thresholds ) ¶

参数

thresholds –

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. volumeOverride ( ) ¶

返回类型

QLevelOfDetailBoundingSphere

另请参阅

setVolumeOverride()

PySide2.Qt3DRender.Qt3DRender.QLevelOfDetail. volumeOverrideChanged ( volumeOverride ) ¶

参数

volumeOverride – QLevelOfDetailBoundingSphere