QQuick3DTextureData Class

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);
    }
};

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

CONFIG += qmltypes
QML_IMPORT_NAME = Example
QML_IMPORT_MAJOR_VERSION = 1

qt_add_qml_module(application
    URI Example
    VERSION 1.0
)

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

import Example 1.0

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