QLevelOfDetail露

PyQt5.Qt3DRender.QLevelOfDetail

Inherits from QComponent.

Description露

The QLevelOfDetail class provides a way of controlling the complexity of rendered entities based on their size on the screen.

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.

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

The 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
...

Enums露

ThresholdType

Specifies how the values in the thresholds are interpreted

Member	Value	Description
DistanceToCameraThreshold	0	Distance from the entity to the selected camera
ProjectedScreenPixelSizeThreshold	1	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.

Methods露

__init__(parent: QNode = None): TODO

camera() → QCamera: See also

setCamera().

createBoundingSphere(QVector3D, float) → QLevelOfDetailBoundingSphere: TODO

currentIndex() → int: See also

setCurrentIndex().

sceneChangeEvent(QSceneChange): TODO

setCamera(QCamera): Sets the camera relative to which distance and size are computed.

See also

camera().

setCurrentIndex(int)

Sets the currentIndex.

Note: 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.

Signals露

cameraChanged(QCamera): TODO

currentIndexChanged(int): TODO

thresholdsChanged(Iterable[float]): TODO

thresholdTypeChanged(ThresholdType): TODO

volumeOverrideChanged(QLevelOfDetailBoundingSphere): TODO