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:

quickitems/Built_with_Qt_RGB_logo_vertical.png

Contents

Qt Quick 3D - Quick Items Example

Quick Items in a Quick 3D Scene

The test scene