- Qt 5.15
- Qt 3D
- C++ Classes
- QAbstractRayCaster
- Qt 5.15.11 Reference Documentation

# QAbstractRayCaster Class

class Qt3DRender::QAbstractRayCaster

An abstract base class for ray casting in 3d scenes. More...

Header: | #include <QAbstractRayCaster>
qmake: | QT += 3drender
Since: | Qt 5.11
Instantiated By: | AbstractRayCaster
Inherits: | Qt3DCore::QComponent
Inherited By: | Qt3DRender::QRayCaster and Qt3DRender::QScreenRayCaster

This class was introduced in Qt 5.11.

- List of all members, including inherited members

## Public Types

enum | FilterMode { AcceptAnyMatchingLayers, AcceptAllMatchingLayers, DiscardAnyMatchingLayers, DiscardAllMatchingLayers }
enum | RunMode { Continuous, SingleShot }

## Properties

- filterMode : FilterMode
- hits : const Hits
- runMode : RunMode

## Public Functions

void | addLayer(QLayer *layer)
FilterMode | filterMode() const
Hits | hits() const
QVector<QLayer *> | layers() const
void | removeLayer(QLayer *layer)
RunMode | runMode() const

## Public Slots

void | setFilterMode(FilterMode filterMode)
void | setRunMode(RunMode runMode)

## Signals

void | filterModeChanged(Qt3DRender::QAbstractRayCaster::FilterMode filterMode)
void | hitsChanged(const Qt3DRender::QAbstractRayCaster::Hits &hits)
void | runModeChanged(Qt3DRender::QAbstractRayCaster::RunMode runMode)

## Detailed Description

Qt3DRender::QAbstractRayCaster is an abstract base class for casting rays into a 3d scene. Qt3DRender::QAbstractRayCaster can not be directly instantiated, but rather through its subclasses. QAbstractRayCaster specifies common properties for all ray casters, such as run mode and layer handling, while leaving the actual ray casting details to the subclasses.

Ray castings differs from picking (using Qt3DRender::QObjectPicker) in that it does not require mouse events to trigger.

By default, the instances of Qt3DRender::QAbstractRayCaster are disabled. When enabled, the specified ray will be tested for intersecting objects at every frame. The QAbstractRayCaster::hits property will be updated with the results of the ray casting, even if no objects are found.

The Qt3DRender::QPickingSettings can be used to control the ray casting, such as which primitives are tested and how the results are returned.

Furthermore, Qt3DRender::QLayer components can be used to control how entities, or entity sub-graphs, react to ray casting.

Note: Components derived from QAbstractRayCaster should not be shared amount multiple entities.

See also Qt3DRender::QRayCaster, Qt3DRender::QScreenRayCaster, Qt3DRender::QObjectPicker, Qt3DRender::QPickingSettings, and Qt3DRender::QNoPicking.

## Member Type Documentation

### enum QAbstractRayCaster::FilterMode

Specifies the rules for selecting entities to test for raycasting.

Constant | Value | Description
--- | --- | ---
`Qt3DRender::QAbstractRayCaster::AcceptAnyMatchingLayers` | `0` | Accept entities that reference one or more QLayer objects added to this QAbstractRayCaster. This is the default
`Qt3DRender::QAbstractRayCaster::AcceptAllMatchingLayers` | `1` | Accept entities that reference all the QLayer objects added to this QAbstractRayCaster
`Qt3DRender::QAbstractRayCaster::DiscardAnyMatchingLayers` | `2` | Discard entities that reference one or more QLayer objects added to this QAbstractRayCaster
`Qt3DRender::QAbstractRayCaster::DiscardAllMatchingLayers` | `3` | Discard entities that reference all QLayer objects added to this QAbstractRayCaster

### enum QAbstractRayCaster::RunMode

This enumeration specifies how often ray casting is performed

Constant | Value | Description
--- | --- | ---
`Qt3DRender::QAbstractRayCaster::Continuous` | `0` | Ray casting is performed at every frame as long as the component is enabled.
`Qt3DRender::QAbstractRayCaster::SingleShot` | `1` | Ray casting is done once then the component disables itself. This is the default

## Property Documentation

### filterMode : FilterMode

Holds the filter mode specifying the entities to select for ray casting tests.

The default value is AcceptMatchingLayers.

Access functions:

FilterMode | filterMode() const
void | setFilterMode(FilterMode filterMode)

Notifier signal:

void | filterModeChanged(Qt3DRender::QAbstractRayCaster::FilterMode filterMode)

### hits : const Hits

Holds the results of last ray casting test as a vector of Qt3DRender::QRayCasterHit instances.

Note that even if successive tests return the exact same results (or empty results), a change notification will be emitted at every test.

Access functions:

Hits | hits() const

Notifier signal:

void | hitsChanged(const Qt3DRender::QAbstractRayCaster::Hits &hits)

### runMode : RunMode

Holds the run mode controlling how often ray casting tests are performed.

If set to SingleShot (the default), when the component is enabled, a single ray casting test will be performed and the component will automatically disable itself.

If set to Continuous, ray casting tests will be performed at every frame as long as the component is enabled.

Access functions:

RunMode | runMode() const
void | setRunMode(RunMode runMode)

Notifier signal:

void | runModeChanged(Qt3DRender::QAbstractRayCaster::RunMode runMode)

## Member Function Documentation

### void QAbstractRayCaster::addLayer(QLayer *layer)

Add layer to the current list of layers

### QVector<QLayer *> QAbstractRayCaster::layers() const

Returns the current list of layers

### void QAbstractRayCaster::removeLayer(QLayer *layer)

Remove layer from the current list of layers