QQuick3DTextureData Class

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

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

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

With CMake, automatic registration is the default behavior, so no special settings are needed beyond basic QML module setup:

qt_add_qml_module(application
    URI Example
    VERSION 1.0
)

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.

ConstantValueDescription
QQuick3DTextureData::None0The color format is not defined
QQuick3DTextureData::RGBA81The color format is considered as 8-bit integer in R, G, B and alpha channels.
QQuick3DTextureData::RGBA16F2The color format is considered as 16-bit float in R,G,B and alpha channels.
QQuick3DTextureData::RGBA32F3The color format is considered as 32-bit float in R, G, B and alpha channels.
QQuick3DTextureData::RGBE84The color format is considered as 8-bit mantissa in the R, G, and B channels and 8-bit shared exponent.
QQuick3DTextureData::R85The color format is considered as 8-bit integer in R channel.
QQuick3DTextureData::R166The color format is considered as 16-bit integer in R channel.
QQuick3DTextureData::R16F7The color format is considered as 16-bit float in R channel.
QQuick3DTextureData::R32F8The color format is considered as 32-bit float R channel.
QQuick3DTextureData::BC19The color format is considred as BC1 compressed format with R, G, B, and alpha channels.
QQuick3DTextureData::BC210The color format is considred as BC2 compressed format with R, G, B, and alpha channels.
QQuick3DTextureData::BC311The color format is considred as BC3 compressed format with R, G, B, and alpha channels.
QQuick3DTextureData::BC412The color format is considred as BC4 compressed format with one color channel.
QQuick3DTextureData::BC513The color format is considred as BC5 compressed format with two color channels.
QQuick3DTextureData::BC6H14The color format is considred as BC6H compressed format with three high dynamic range color channels.
QQuick3DTextureData::BC715The color format is considred as BC7 compressed format with R, G, B, and alpha channels.
QQuick3DTextureData::DXT1_RGBA16The color format is considered as DXT1 compressed format with R, G, B and alpha channels.
QQuick3DTextureData::DXT1_RGB17The color format is considered as DXT1 compressed format with R, G and B channels.
QQuick3DTextureData::DXT3_RGBA18The color format is considered as DXT3 compressed format with R, G, B and alpha channels.
QQuick3DTextureData::DXT5_RGBA19The color format is considered as DXT5 compressed format with R, G, B and alpha channels.
QQuick3DTextureData::ETC2_RGB820The color format is considered as ETC2 compressed format for RGB888 data
QQuick3DTextureData::ETC2_RGB8A121The color format is considered as ETC2 compressed format for RGBA data where alpha is 1-bit.
QQuick3DTextureData::ETC2_RGBA822The color format is considered as ETC2 compressed format with RGBA8888 data.
QQuick3DTextureData::ASTC_4x423The color format is considered as ASTC compressed format with 4x4 block footprint.
QQuick3DTextureData::ASTC_5x424The color format is considered as ASTC compressed format with 5x4 block footprint.
QQuick3DTextureData::ASTC_5x525The color format is considered as ASTC compressed format with 5x5 block footprint.
QQuick3DTextureData::ASTC_6x526The color format is considered as ASTC compressed format with 6x5 block footprint.
QQuick3DTextureData::ASTC_6x627The color format is considered as ASTC compressed format with 6x6 block footprint.
QQuick3DTextureData::ASTC_8x528The color format is considered as ASTC compressed format with 8x5 block footprint.
QQuick3DTextureData::ASTC_8x629The color format is considered as ASTC compressed format with 8x6 block footprint.
QQuick3DTextureData::ASTC_8x830The color format is considered as ASTC compressed format with 8x8 block footprint.
QQuick3DTextureData::ASTC_10x531The color format is considered as ASTC compressed format with 10x5 block footprint.
QQuick3DTextureData::ASTC_10x632The color format is considered as ASTC compressed format with 10x6 block footprint.
QQuick3DTextureData::ASTC_10x833The color format is considered as ASTC compressed format with 10x8 block footprint.
QQuick3DTextureData::ASTC_10x1034The color format is considered as ASTC compressed format with 10x10 block footprint.
QQuick3DTextureData::ASTC_12x1035The color format is considered as ASTC compressed format with 12x10 block footprint.
QQuick3DTextureData::ASTC_12x1236The 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().

© 2021 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.