Qt Quick 3D - Quick Items Example

Demonstrates the use of Qt Quick Items in Quick 3D scene.

This example demonstrates using Qt Quick 2D items in the Quick 3D scene.

Quick Items in a Quick 3D Scene

Qt Quick 2D Items can be added into Quick 3D scenes with some limitations and considerations. When using Qt Quick Items there are a few things to note:

  • When an Item is inside a Node, it is automatically centered and the Item's transforms (x, y, rotation etc.) are ignored. Instead, transforms should be added for the parent Node. If more than one Item should be affected by the same transform, then these items can be grouped together under a common parent Item.
  • Items do not receive touch/mouse events e.g. with MouseArea, so they should be non-interactive.
  • Quick items are not affect by lights and shadows as they are rendered by the 2D Scenegraph.

The test scene

The important parts of this example are the scene content of the View3D element.

We start by adding the layer furthest away from the camera. This layer contains Rectangle, Text and Image elements. To ensure that the elements in the layer are positioned correctly they are grouped together under a common parent Item. Note that all content is clipped inside this root item so it needs to be sized appropriately.

Node {
    position: Qt.vector3d(0, 100, -120)
    Item {
        width: 400
        height: 400
        Rectangle {
            anchors.fill: parent
            opacity: 0.4
            color: "#202020"
            radius: 10
            border.width: 2
            border.color: "#f0f0f0"
        }
        Text {
            anchors.top: parent.top
            anchors.topMargin: 10
            anchors.horizontalCenter: parent.horizontalCenter
            font.pixelSize: 20
            color: "#e0e0e0"
            style: Text.Raised
            text: qsTr("Background Item")
        }
        Image {
            anchors.centerIn: parent
            source: "Built_with_Qt_RGB_logo_vertical"
        }
    }
}

Next Node and its items are positioned a bit closer to the camera. It contains three Rectangle items which animate both the x position and the rotation. Note that the animations are done on the parent Node while the content of the Quick Item remains static. From a performance perspective this is a good approach with more complex items.

Node {
    position: Qt.vector3d(0, 150, 100)
    SequentialAnimation on x {
        loops: Animation.Infinite
        NumberAnimation {
            to: -200
            duration: 1500
            easing.type: Easing.InOutQuad
        }
        NumberAnimation {
            to: 200
            duration: 1500
            easing.type: Easing.InOutQuad
        }
    }
    NumberAnimation on eulerRotation.z {
        loops: Animation.Infinite
        from: 0
        to: 360
        duration: 4000
        easing.type: Easing.InOutBack
    }
    Item {
        width: 400
        height: 400
        // This allows rendering into offscreen surface and caching it.
        layer.enabled: true
        Rectangle {
            x: 150
            y: 100
            width: 100
            height: 100
            radius: 50
            color: "#80808020"
            border.color: "black"
            border.width: 2
        }
        Rectangle {
            x: 90
            y: 200
            width: 100
            height: 100
            radius: 50
            color: "#80808020"
            border.color: "black"
            border.width: 2
        }
        Rectangle {
            x: 210
            y: 200
            width: 100
            height: 100
            radius: 50
            color: "#80808020"
            border.color: "black"
            border.width: 2
        }
    }
}

The third item layer of this example contains a single Text item with an opacity animation. The Text item is automatically centered into the parent Node.

Node {
    position: Qt.vector3d(0, 80, 250)
    Text {
        width: 300
        wrapMode: Text.WordWrap
        horizontalAlignment: Text.AlignJustify
        font.pixelSize: 14
        color: "#e0e0e0"
        style: Text.Raised
        text: "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod " +
              "tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim " +
              "veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea " +
              "commodo consequat."
        SequentialAnimation on opacity {
            loops: Animation.Infinite
            NumberAnimation {
                to: 0
                duration: 1500
                easing.type: Easing.InOutQuad
            }
            NumberAnimation {
                to: 1
                duration: 1500
                easing.type: Easing.InOutQuad
            }
        }
    }
}

To visualize z-ordering of the above Quick Item layers, we will also setup a model for the 3D wrecking ball. It animates rotation around the top Node, which makes the sphere move through the other layers.

Node {
    position: Qt.vector3d(0, 800, 0)
    SequentialAnimation on eulerRotation.x {
        loops: Animation.Infinite
        NumberAnimation {
            to: 20
            duration: 3500
            easing.type: Easing.InOutQuad
        }
        NumberAnimation {
            to: -20
            duration: 3500
            easing.type: Easing.InOutQuad
        }
    }
    Model {
        source: "#Cylinder"
        y: -300
        scale: Qt.vector3d(0.1, 6.1, 0.1)
        materials: DefaultMaterial {
            diffuseColor: Qt.rgba(0.9, 0.9, 0.9, 1.0)
        }
    }
    Model {
        source: "#Sphere"
        y: -700
        scale: Qt.vector3d(2, 2, 2)
        materials: DefaultMaterial {
            diffuseColor: Qt.rgba(0.4, 0.4, 0.4, 1.0)
        }
    }
}

Files:

Images:

© 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.