- Qt 6.4
- Qt 3D
- C++ Classes
- Qt3DCore
- QBoundingVolume
- Qt 6.4.3 Reference Documentation

# QBoundingVolume Class

class Qt3DCore::QBoundingVolume

can be used to override the bounding volume of an entity. More...

Header: | #include <Qt3DCore/QBoundingVolume>
CMake: | find_package(Qt6 REQUIRED COMPONENTS 3dcore) target_link_libraries(mytarget PRIVATE Qt6::3dcore)
qmake: | QT += 3dcore
Since: | Qt 6.0
Instantiated By: | BoundingVolume
Inherits: | Qt3DCore::QComponent
Inherited By: | Qt3DRender::QGeometryRenderer and Qt3DRender::QPickingProxy

- List of all members, including inherited members

## Properties

implicitMaxPoint : const QVector3D implicitMinPoint : const QVector3D implicitPointsValid : const bool | maxPoint : QVector3D minPoint : QVector3D view : QGeometryView*

## Public Functions

| QBoundingVolume(Qt3DCore::QNode *parent = nullptr)
bool | areImplicitPointsValid() const
QVector3D | implicitMaxPoint() const
QVector3D | implicitMinPoint() const
QVector3D | maxPoint() const
QVector3D | minPoint() const
Qt3DCore::QGeometryView * | view() const

## Public Slots

void | setMaxPoint(const QVector3D &maxPoint)
void | setMinPoint(const QVector3D &minPoint)
void | setView(Qt3DCore::QGeometryView *view)
bool | updateImplicitBounds()

## Signals

void | implicitMaxPointChanged(const QVector3D &implicitMaxPoint)
void | implicitMinPointChanged(const QVector3D &implicitMinPoint)
void | implicitPointsValidChanged(bool implicitPointsValid)
void | maxPointChanged(QVector3D maxPoint)
void | minPointChanged(QVector3D minPoint)
void | viewChanged(Qt3DCore::QGeometryView *view)

## Detailed Description

An entity's bounding volume is used for many operations such as picking or view frustum culling. It is normally computed by traversing the rendered geometry.

QBoundingVolume can be used when the extent of the geometry is known to the application so that Qt 3D does not have to compute it.

A bounding volume can be provided either as minimum and maximum extent coordinates, or a separate, usually simpler, geometry that approximates the rendered mesh.

When using minimum and maximum extents, these are considered to be the opposite corners of an axis aligned bounding box, in the geometry's local coordinate system.

QBoundingVolume can also be used to query the computed bounding volume of a GeometryView. The implicitMinPoint and implicitMaxPoint properties will be updated if the geometry changes. Note that this is done asynchronously on a background thread so you should check the value of implicitPointsValid before reading them.

You can force the implicit extents to be updated by calling updateImplicitBounds. This will block on the calling thread until the results are available.

Note: GeometryRenderer inherits BoundingVolume and thus supports reading implicit bounds or setting explicit bounds also.

## Property Documentation

### `[read-only]` implicitMaxPoint : const QVector3D

* * * Holds maximum extent of the bounding volume computed from the specified view.

Access functions:

QVector3D | implicitMaxPoint() const

Notifier signal:

void | implicitMaxPointChanged(const QVector3D &implicitMaxPoint)

### `[read-only]` implicitMinPoint : const QVector3D

* * * Holds minimum extent of the bounding volume computed from the specified view.

Access functions:

QVector3D | implicitMinPoint() const

Notifier signal:

void | implicitMinPointChanged(const QVector3D &implicitMinPoint)

### `[read-only]` implicitPointsValid : const bool

* * * True if a view has been assigned and the implicit extent properties are up to date. * *

Access functions:

bool | areImplicitPointsValid() const

Notifier signal:

void | implicitPointsValidChanged(bool implicitPointsValid)

See also updateImplicitBounds.

### maxPoint : QVector3D

* * * User specified maximum extent of the bounding volume. When set (along with minimum * extent), this will be used internally to avoid computing the volume from the * geometry.

Access functions:

QVector3D | maxPoint() const
void | setMaxPoint(const QVector3D &maxPoint)

Notifier signal:

void | maxPointChanged(QVector3D maxPoint)

### minPoint : QVector3D

* * * User specified minimum extent of the bounding volume. When set (along with maximum * extent), this will be used internally to avoid computing the volume from the * geometry.

Access functions:

QVector3D | minPoint() const
void | setMinPoint(const QVector3D &minPoint)

Notifier signal:

void | minPointChanged(QVector3D minPoint)

### view : QGeometryView*

* * * Holds a pointer to the instance of QGeometryView which will be used, if set, * to compute the bounding volume.

Access functions:

Qt3DCore::QGeometryView * | view() const
void | setView(Qt3DCore::QGeometryView *view)

Notifier signal:

void | viewChanged(Qt3DCore::QGeometryView *view)

## Member Function Documentation

### QBoundingVolume::QBoundingVolume(Qt3DCore::QNode *parent = nullptr)

Constructs a new QBoundingVolume with parent.

### `[slot]` bool QBoundingVolume::updateImplicitBounds()

* Updates the implicit bounds of the specified view. Returns * `true` if the computation succeeded and false otherwise. * *

Note: The calculations are done in the call thread, this * could take significant time for large meshes.