QQuick3DTextureData Class

Base class for defining custom texture data. More...

Header:	#include <QQuick3DTextureData>
Since:	Qt 6.0
Instantiated By:	TextureData
Inherits:	QQuick3DObject

• List of all members, including inherited members

Public Types

enum	Format { None, RGBA8, RGBA16F, RGBA32F, RGBE8, …, ASTC_12x12 }

Public Functions

QQuick3DTextureData::Format	format() const
bool	hasTransparency() const
void	setFormat(QQuick3DTextureData::Format format)
void	setHasTransparency(bool hasTransparency)
void	setSize(const QSize &size)
void	setTextureData(const QByteArray &data)
QSize	size() const
const QByteArray	textureData() const

Detailed Description

The QQuick3DTextureData class can be used to specify custom texture data for a Texture in a Qt Quick 3D scene.

While not strictly required, the typical usage is to inherit from this class. The subclass is then exposed to QML by registering it to the type system. The textureData property of a Texture can then be set to reference an instance of the registered type.

Example implementation:

class CustomTextureData : public QQuick3DTextureData
{
    Q_OBJECT
    ... properties ...

public:
    CustomTextureData() { regenerateTextureData(); }

    void setProperty(...)
    {
        // Change relevant internal data.
        // ...

        // Update the texture data
        regenerateTextureData();

        // Finally, trigger an update. This is relevant in case nothing else
        // is changed in the scene; this way we make sure a new frame will
        // be rendered
        update();
    }
private:
    void regenerateTextureData()
    {
        QByteArray textureData;
        textureData = generateTextureData();
        setTextureData(textureData);
        setSize(QSize(256, 256));
        setFormat(QQuick3DTextureData::Format::RGBA8)
        setHasTransparency(true);
    }
};

This class can then be registered as a QML type and used with Texture.

In Qt 5 type registration happened with qmlRegisterType:

qmlRegisterType<MyCustomTextureData>("Example", 1, 0, "MyCustomTextureData");

In Qt 6 the default approach is to use automatic registration with the help of the build system. Instead of calling qmlRegisterType, the .pro file can now contain:

CONFIG += qmltypes
QML_IMPORT_NAME = Example
QML_IMPORT_MAJOR_VERSION = 1

Alternatively, with CMake the equivalent is:

set_target_properties(application PROPERTIES
    QT_QML_MODULE_VERSION 1.0
    QT_QML_MODULE_URI Example
)
qt6_qml_type_registration(application)

The class implementation should add QML_NAMED_ELEMENT:

class CustomTextureData : public QQuick3DTextureData
{
    Q_OBJECT
    QML_NAMED_ELEMENT(MyCustomTextureData)
    ...
};

The QML code can then use the custom type:

import Example 1.0

Model {
    source: "#Cube"
    materials: [
        DefaultMaterial {
            diffuseMap: diffuseMapCustomTexture
        }
    ]
    Texture {
        id: diffuseMapCustomTexture
        textureData: MyCustomTextureData { }
    }
}

Member Type Documentation

enum QQuick3DTextureData::Format

Returns the color format of the texture data assigned in textureData property.

Constant	Value	Description
QQuick3DTextureData::None	0	The color format is not defined
QQuick3DTextureData::RGBA8	1	The color format is considered as 8-bit integer in R, G, B and alpha channels.
QQuick3DTextureData::RGBA16F	2	The color format is considered as 16-bit float in R,G,B and alpha channels.
QQuick3DTextureData::RGBA32F	3	The color format is considered as 32-bit float in R, G, B and alpha channels.
QQuick3DTextureData::RGBE8	4	The color format is considered as 8-bit mantissa in the R, G, and B channels and 8-bit shared exponent.
QQuick3DTextureData::R8	5	The color format is considered as 8-bit integer in R channel.
QQuick3DTextureData::R16	6	The color format is considered as 16-bit integer in R channel.
QQuick3DTextureData::R16F	7	The color format is considered as 16-bit float in R channel.
QQuick3DTextureData::R32F	8	The color format is considered as 32-bit float R channel.
QQuick3DTextureData::BC1	9	The color format is considred as BC1 compressed format with R, G, B, and alpha channels.
QQuick3DTextureData::BC2	10	The color format is considred as BC2 compressed format with R, G, B, and alpha channels.
QQuick3DTextureData::BC3	11	The color format is considred as BC3 compressed format with R, G, B, and alpha channels.
QQuick3DTextureData::BC4	12	The color format is considred as BC4 compressed format with one color channel.
QQuick3DTextureData::BC5	13	The color format is considred as BC5 compressed format with two color channels.
QQuick3DTextureData::BC6H	14	The color format is considred as BC6H compressed format with three high dynamic range color channels.
QQuick3DTextureData::BC7	15	The color format is considred as BC7 compressed format with R, G, B, and alpha channels.
QQuick3DTextureData::DXT1_RGBA	16	The color format is considered as DXT1 compressed format with R, G, B and alpha channels.
QQuick3DTextureData::DXT1_RGB	17	The color format is considered as DXT1 compressed format with R, G and B channels.
QQuick3DTextureData::DXT3_RGBA	18	The color format is considered as DXT3 compressed format with R, G, B and alpha channels.
QQuick3DTextureData::DXT5_RGBA	19	The color format is considered as DXT5 compressed format with R, G, B and alpha channels.
QQuick3DTextureData::ETC2_RGB8	20	The color format is considered as ETC2 compressed format for RGB888 data
QQuick3DTextureData::ETC2_RGB8A1	21	The color format is considered as ETC2 compressed format for RGBA data where alpha is 1-bit.
QQuick3DTextureData::ETC2_RGBA8	22	The color format is considered as ETC2 compressed format with RGBA8888 data.
QQuick3DTextureData::ASTC_4x4	23	The color format is considered as ASTC compressed format with 4x4 block footprint.
QQuick3DTextureData::ASTC_5x4	24	The color format is considered as ASTC compressed format with 5x4 block footprint.
QQuick3DTextureData::ASTC_5x5	25	The color format is considered as ASTC compressed format with 5x5 block footprint.
QQuick3DTextureData::ASTC_6x5	26	The color format is considered as ASTC compressed format with 6x5 block footprint.
QQuick3DTextureData::ASTC_6x6	27	The color format is considered as ASTC compressed format with 6x6 block footprint.
QQuick3DTextureData::ASTC_8x5	28	The color format is considered as ASTC compressed format with 8x5 block footprint.
QQuick3DTextureData::ASTC_8x6	29	The color format is considered as ASTC compressed format with 8x6 block footprint.
QQuick3DTextureData::ASTC_8x8	30	The color format is considered as ASTC compressed format with 8x8 block footprint.
QQuick3DTextureData::ASTC_10x5	31	The color format is considered as ASTC compressed format with 10x5 block footprint.
QQuick3DTextureData::ASTC_10x6	32	The color format is considered as ASTC compressed format with 10x6 block footprint.
QQuick3DTextureData::ASTC_10x8	33	The color format is considered as ASTC compressed format with 10x8 block footprint.
QQuick3DTextureData::ASTC_10x10	34	The color format is considered as ASTC compressed format with 10x10 block footprint.
QQuick3DTextureData::ASTC_12x10	35	The color format is considered as ASTC compressed format with 12x10 block footprint.
QQuick3DTextureData::ASTC_12x12	36	The color format is considered as ASTC compressed format with 12x12 block footprint.

Note: With the exception of RGBA8, not every format is supported at runtime as this depends on which backend is being used as well which hardware is being used.

Note: RGBE is internally represented as an RGBA8 but is intepreted as described when used as a lightProbe or skybox texture.

Note: Using the value None will assume the default value of RGBA8

Member Function Documentation

QQuick3DTextureData::Format QQuick3DTextureData::format() const

Returns the format of the texture data.

See also setFormat().

bool QQuick3DTextureData::hasTransparency() const

Returns true if the texture data has transparency.

The default value is false.

See also setHasTransparency().

void QQuick3DTextureData::setFormat(QQuick3DTextureData::Format format)

Sets the format of the texture data.

The default format is /c RGBA8

See also format().

void QQuick3DTextureData::setHasTransparency(bool hasTransparency)

Set hasTransparency to true if the texture data has an active alpha channel with non-opaque values.

This is used as an optimization by the engine so that for formats that do support an alpha channel do not need to have each value checked for non-opaque values.

See also hasTransparency().

void QQuick3DTextureData::setSize(const QSize &size)

Sets the size of the texture data in pixels.

See also size().

void QQuick3DTextureData::setTextureData(const QByteArray &data)

Sets the texture data. The contents of data must respect the size and format properties as the backend will try and upload and use the data as if it were a texture of size and format, and if there is any deviation the result will be somewhere between incorrect rendering of the texture, or potentially a crash.

See also textureData().

QSize QQuick3DTextureData::size() const

Returns the size of the texture data in pixels.

See also setSize().

const QByteArray QQuick3DTextureData::textureData() const

Returns the current texture data defined by this item.

See also setTextureData().