- Qt 5.15
- Qt Data Visualization
- C++ Classes
- Q3DScene
- Qt Data Visualization | Commercial or GPLv3

# Q3DScene Class

Q3DScene class provides description of the 3D scene being visualized. More...

Header: | #include <Q3DScene>
qmake: | QT += datavisualization
Since: | QtDataVisualization 1.0
Instantiated By: | Scene3D
Inherits: | QObject

This class was introduced in QtDataVisualization 1.0.

- List of all members, including inherited members

## Properties

- activeCamera : Q3DCamera*
- activeLight : Q3DLight*
- devicePixelRatio : float
- graphPositionQuery : QPoint
- primarySubViewport : QRect

- secondarySubViewport : QRect
- secondarySubviewOnTop : bool
- selectionQueryPosition : QPoint
- slicingActive : bool
- viewport : const QRect

## Public Functions

| Q3DScene(QObject *parent = nullptr)
virtual | ~Q3DScene()
Q3DCamera * | activeCamera() const
Q3DLight * | activeLight() const
float | devicePixelRatio() const
QPoint | graphPositionQuery() const
bool | isPointInPrimarySubView(const QPoint &point)
bool | isPointInSecondarySubView(const QPoint &point)
bool | isSecondarySubviewOnTop() const
bool | isSlicingActive() const
QRect | primarySubViewport() const
QRect | secondarySubViewport() const
QPoint | selectionQueryPosition() const
void | setActiveCamera(Q3DCamera *camera)
void | setActiveLight(Q3DLight *light)
void | setDevicePixelRatio(float pixelRatio)
void | setGraphPositionQuery(const QPoint &point)
void | setPrimarySubViewport(const QRect &primarySubViewport)
void | setSecondarySubViewport(const QRect &secondarySubViewport)
void | setSecondarySubviewOnTop(bool isSecondaryOnTop)
void | setSelectionQueryPosition(const QPoint &point)
void | setSlicingActive(bool isSlicing)
QRect | viewport() const

## Signals

void | activeCameraChanged(Q3DCamera *camera)
void | activeLightChanged(Q3DLight *light)
void | devicePixelRatioChanged(float pixelRatio)
void | graphPositionQueryChanged(const QPoint &position)
void | primarySubViewportChanged(const QRect &subViewport)
void | secondarySubViewportChanged(const QRect &subViewport)
void | secondarySubviewOnTopChanged(bool isSecondaryOnTop)
void | selectionQueryPositionChanged(const QPoint &position)
void | slicingActiveChanged(bool isSlicingActive)
void | viewportChanged(const QRect &viewport)

## Static Public Members

QPoint | invalidSelectionPoint()

## Detailed Description

The 3D scene contains a single active camera and a single active light source. Visualized data is assumed to be at a fixed location.

The 3D scene also keeps track of the viewport in which visualization rendering is done, the primary subviewport inside the viewport where the main 3D data visualization view resides and the secondary subviewport where the 2D sliced view of the data resides. The subviewports are by default resized by the Q3DScene. To override the resize behavior you need to listen to both viewportChanged() and slicingActiveChanged() signals and recalculate the subviewports accordingly.

Also the scene has flag for tracking if the secondary 2D slicing view is currently active or not.

Note: Not all visualizations support the secondary 2D slicing view.

## Property Documentation

### activeCamera : Q3DCamera*

This property holds the currently active camera in the 3D scene.

When a new Q3DCamera object is set, it is automatically added as child of the scene.

Access functions:

Q3DCamera * | activeCamera() const
void | setActiveCamera(Q3DCamera *camera)

Notifier signal:

void | activeCameraChanged(Q3DCamera *camera)

### activeLight : Q3DLight*

This property holds the currently active light in the 3D scene.

When a new Q3DLight objects is set, it is automatically added as child of the scene.

Access functions:

Q3DLight * | activeLight() const
void | setActiveLight(Q3DLight *light)

Notifier signal:

void | activeLightChanged(Q3DLight *light)

### devicePixelRatio : float

This property holds the device pixel ratio that is used when mapping input coordinates to pixel coordinates.

Access functions:

float | devicePixelRatio() const
void | setDevicePixelRatio(float pixelRatio)

Notifier signal:

void | devicePixelRatioChanged(float pixelRatio)

### graphPositionQuery : QPoint

This property holds the coordinates for the user input that should be processed by the scene as a graph position query.

If this property is set to a value other than invalidSelectionPoint(), the graph tries to match a graph position to the specified coordinates within the primary viewport. After the rendering pass, this property is returned to its default state of invalidSelectionPoint(). The queried graph position can be read from the QAbstract3DGraph::queriedGraphPosition property after the next render pass.

There is no single correct 3D coordinate to match a particular screen position, so to be consistent, the queries are always done against the inner sides of an invisible box surrounding the graph.

Note: Bar graphs allow graph position queries only at the graph floor level.

Access functions:

QPoint | graphPositionQuery() const
void | setGraphPositionQuery(const QPoint &point)

Notifier signal:

void | graphPositionQueryChanged(const QPoint &position)

See also QAbstract3DGraph::queriedGraphPosition.

### primarySubViewport : QRect

This property holds the current subviewport rectangle inside the viewport where the primary view of the data visualization is targeted.

If isSlicingActive() is `false`, the primary sub viewport is equal to viewport(). If isSlicingActive() is `true` and the primary sub viewport has not been explicitly set, it will be one fifth of viewport().

Note: Setting primarySubViewport larger than or outside of the viewport resizes the viewport accordingly.

Access functions:

QRect | primarySubViewport() const
void | setPrimarySubViewport(const QRect &primarySubViewport)

Notifier signal:

void | primarySubViewportChanged(const QRect &subViewport)

### secondarySubViewport : QRect

This property holds the secondary viewport rectangle inside the viewport.

The secondary viewport is used for drawing the 2D slice view in some visualizations. If it has not been explicitly set, it will be equal to QRect. If isSlicingActive() is `true`, it will be equal to viewport.

Note: If the secondary sub viewport is larger than or outside of the viewport, the viewport is resized accordingly.

Access functions:

QRect | secondarySubViewport() const
void | setSecondarySubViewport(const QRect &secondarySubViewport)

Notifier signal:

void | secondarySubViewportChanged(const QRect &subViewport)

### secondarySubviewOnTop : bool

This property holds whether the 2D slicing view or the 3D view is drawn on top.

Access functions:

bool | isSecondarySubviewOnTop() const
void | setSecondarySubviewOnTop(bool isSecondaryOnTop)

Notifier signal:

void | secondarySubviewOnTopChanged(bool isSecondaryOnTop)

### selectionQueryPosition : QPoint

This property holds the coordinates for the user input that should be processed by the scene as a selection.

If this property is set to a value other than invalidSelectionPoint(), the graph tries to select a data item, axis label, or a custom item at the specified coordinates within the primary viewport. After the rendering pass, the property is returned to its default state of invalidSelectionPoint().

Access functions:

QPoint | selectionQueryPosition() const
void | setSelectionQueryPosition(const QPoint &point)

Notifier signal:

void | selectionQueryPositionChanged(const QPoint &position)

See also QAbstract3DGraph::selectedElement.

### slicingActive : bool

This property holds whether the 2D slicing view is currently active.

If `true`, QAbstract3DGraph::selectionMode must have either QAbstract3DGraph::SelectionRow or QAbstract3DGraph::SelectionColumn set to a valid selection.

Note: Not all visualizations support the 2D slicing view.

Access functions:

bool | isSlicingActive() const
void | setSlicingActive(bool isSlicing)

Notifier signal:

void | slicingActiveChanged(bool isSlicingActive)

### viewport : const QRect

This property holds a read only property that contains the current viewport rectangle where all the 3D rendering is targeted.

Access functions:

QRect | viewport() const

Notifier signal:

void | viewportChanged(const QRect &viewport)

## Member Function Documentation

### Q3DScene::Q3DScene(QObject *parent = nullptr)

Constructs a basic scene with one light and one camera in it. An optional parent parameter can be given and is then passed to QObject constructor.

### `[virtual]` Q3DScene::~Q3DScene()

Destroys the 3D scene and all the objects contained within it.

### `[static]` QPoint Q3DScene::invalidSelectionPoint()

Returns a QPoint signifying an invalid selection position.

### bool Q3DScene::isPointInPrimarySubView(const QPoint &point)

Returns whether the given point resides inside the primary subview or not. Returns `true` if the point is inside the primary subview.

Note: If subviews are superimposed, and the given point resides inside both, result is `true` only when the primary subview is on top.

### bool Q3DScene::isPointInSecondarySubView(const QPoint &point)

Returns whether the given point resides inside the secondary subview or not. Returns `true` if the point is inside the secondary subview.

Note: If subviews are superimposed, and the given point resides inside both, result is `true` only when the secondary subview is on top.