QLevelOfDetail

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

Inheritance diagram of PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail

Inherited by: QLevelOfDetailSwitch

Synopsis

Functions

Detailed Description

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);
QList<qreal> thresholds = {20, 35, 50, 65};
lod->setThresholds(thresholds);
lod->setCamera(mainCamera);
renderableEntity->addComponent(lod);

// connect to QLevelOfDetail::currentIndexChanged to toggle rendering
...
class PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail([parent=None])
Parameters

parentPySide6.Qt3DCore.Qt3DCore.QNode

Constructs a new QLevelOfDetail with the specified parent.

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.ThresholdType

Specifies how the values in the thresholds are interpreted

Constant

Description

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.

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.camera()
Return type

PySide6.Qt3DRender.Qt3DRender.QCamera

See also

setCamera()

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.cameraChanged(camera)
Parameters

cameraPySide6.Qt3DRender.Qt3DRender.QCamera

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.createBoundingSphere(center, radius)
Parameters
Return type

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetailBoundingSphere

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.currentIndex()
Return type

int

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.currentIndexChanged(currentIndex)
Parameters

currentIndex – int

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.setCamera(camera)
Parameters

cameraPySide6.Qt3DRender.Qt3DRender.QCamera

Sets the camera relative to which distance and size are computed.

See also

camera()

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.setCurrentIndex(currentIndex)
Parameters

currentIndex – 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.

See also

currentIndex()

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.setThresholdType(thresholdType)
Parameters

thresholdTypeThresholdType

Sets the way thresholds values are interpreted with parameter thresholdType

See also

thresholdType() ThresholdType

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.setThresholds(thresholds)
Parameters

thresholds

Sets the range values in thresholds.

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.setVolumeOverride(volumeOverride)
Parameters

volumeOverridePySide6.Qt3DRender.Qt3DRender.QLevelOfDetailBoundingSphere

See also

volumeOverride()

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.thresholdType()
Return type

ThresholdType

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.thresholdTypeChanged(thresholdType)
Parameters

thresholdTypeThresholdType

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.thresholds()
Return type

See also

setThresholds()

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.thresholdsChanged(thresholds)
Parameters

thresholds

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.volumeOverride()
Return type

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetailBoundingSphere

PySide6.Qt3DRender.Qt3DRender.QLevelOfDetail.volumeOverrideChanged(volumeOverride)
Parameters

volumeOverridePySide6.Qt3DRender.Qt3DRender.QLevelOfDetailBoundingSphere