[Interest] [Qt3d] Does the duration of NumberAnimation update when you change its value?

[Ramy Atalla]

Hi DR. SeanThanks for reply.I tried both methods none of them works, Overall I think I have a problem controlling the animation (start/stop/restart).I have a slider which generates a value between 0-5000 for the duration of the animation, On value change of the slider it calls a function which does the follow:(1)stops the animation(doesn't work,however console log for animation.running updates to false). (2)updates the value of the property "carspeed".(3) restarts the animation(doesn't work,however console log for animation.running updates to true).
I know there is something implemented wrong.If I initialize the animation running:true it won't stop and if I initialize it to running:false it won't start.
Car.qml (one wheel and one rim transform)

Transform {    id: wheel1Transform    property real userAngle: 0.0    translation:Qt.vector3d(-1.35, 0.368, 1.8)    rotation: fromAxisAndAngle(Qt.vector3d(1, 0, 0), userAngle)}Transform {    id: rim1Transform    property real userAngle: 0.0    translation:Qt.vector3d(-1.40, 0.368, 1.8)    rotation: fromAxisAndAngle(Qt.vector3d(1, 0, 0), userAngle)}

Car.qml (wheeling and rim rotation animation)

 property alias wheelanimationControl : wheelanimationMain   property real carspeed:2000QQ2.SequentialAnimation {    id :wheelanimationMain    running: false    loops: QQ2.Animation.Infinite
QQ2.NumberAnimation {    id:wheelanimation    targets:[ wheel1Transform, rim1Transform,wheel2Transform , rim2Transform,wheel3Transform , rim3Transform,wheel4Transform , rim4Transform]    properties: "userAngle"    duration: carspeed    from: 0    to: 360    alwaysRunToEnd:false   // onDurationChanged: wheelanimationMain.restart()}}
Car.qml (the function that the slider will use)

function sliderValue(){    console.log("before",wheel1Transform.userAngle,wheelanimationMain.running,slider.value, rootcar.carspeed)      wheelanimationMain.stop();      wheelanimationMain.running=false;  // redundant step  
      rootcar.carspeed = slider.value;      wheelanimationMain.restart();      wheelanimationMain.running=true; // redundant step     console.log("after",wheel1Transform.userAngle,wheelanimationMain.running,slider.value, rootcar.carspeed)
}
Slider.qml

import QtQuick 2.5import QtQuick.Controls 1.4
Item {    id :root    width: 300    height: 80
    Rectangle {        id: rectangle1        x: 696        y: 30        width: 300        height: 80        color: "#202020"        radius: 1        border.color: "#ffffff"        opacity: 0.5               }    Text {        id: text1        x: 705        y: 33        color: "#ffffff"        text: qsTr("Speed")        horizontalAlignment: Text.AlignHCenter        verticalAlignment: Text.AlignVCenter        font.pixelSize: 13    }
    MouseArea {        id: mouseArea1        x: 696        y: 30        width: 300        height: 80        onClicked: root.visible=false        cursorShape: Qt.PointingHandCursor    }     Car{ id:car }
    Slider{        id:slider        x: 716        y: 68        width: 263        height: 22        maximumValue: 5000        stepSize: 100        updateValueWhileDragging :true        onValueChanged: car.sliderValue()   }    Label {        x: 910        y: 45        width: 63        height: 16        color: "#ffffff"        text: Math.floor(slider.value/10)+" MPH"        horizontalAlignment: Text.AlignHCenter    }
    Rectangle {        id: rectangle2        x: 600        y: 30        width: 80        height: 80        color: "#202020"        radius: 1        border.color: "#ffffff"        opacity: 0.5               }    Text {        id: text2        x: 600        y: 33        color: "#ffffff"        text: qsTr("run")        horizontalAlignment: Text.AlignHCenter        verticalAlignment: Text.AlignVCenter        font.pixelSize: 13    }
    MouseArea {        id: mouseArea2        x: 600        y: 30        width: 80        height: 80        onClicked: car.wheelanimationControl.running=true;        cursorShape: Qt.PointingHandCursor    }}Thanks,Ramy


---------------------------------------------------------------
Hi,I don't think this works unless you stop/restart the animation which is not 
ideal. A work around is to have a simple NumberAnimation changing a "progress" 
value, then in your actual property that you wish to animate, multiply this 
progress property by your rotationSpeed property. It requires some extra 
gymnastics to cope with non-integer numbers of rotations per cycle of the 
progress property.

Something like this should do it (not tested):

Entity {
    id: root
    property real progress: 0.0
    property real rotationSpeed: 10.0
    property real angle: previousAngle + ( progress * rotationSpeed )
    property real previousAngle: 0.0

    function updatePreviousRotation() {
        root.previousAngle = root.angle;
    }

    SequentialAnimation {
        running: true
        loops: Animation.Infinite
        
        NumberAnimation {
            from: 0; to: 1
            duration: 1000
        }

        ScriptAction { script: updatePreviousRotation() }
    }
}

This is a limitation of what can be expressed with the Qt Quick 2 animation 
framework at present. When we look at adding an animation aspect to Qt 3D for 
Qt 5.8 or 5.9, this is one of the things I want to address along with morph 
target, key frame and skeletal animations. More likely for 5.9 given we're 
already well into the development cycle for 5.8 and we're still putting all 
efforts into 5.7.

Hope this helps,

Sean
--
Dr Sean Harmer | sean.harmer at kdab.com | Managing Director UK
Klarälvdalens Datakonsult AB, a KDAB Group company
Tel. UK +44 (0)1625 809908, Sweden (HQ) +46-563-540090
KDAB - Qt Experts - Platform-independent software solutions


---------------------------------------------------------------Hi,I am trying to do a rotation animation and control the rotation speed by changing the value of the duration, But it doesn't work . My question is it feasible or there another way ?

QQ2.NumberAnimation {    id:wheelanimation     property int carspeed:0    targets: [wheel1Transform , rim1Transform,wheel2Transform , rim2Transform,wheel3Transform ,             rim3Transform,wheel4Transform , rim4Transform]    property: "userAngle"    duration: carspeed    from: 0    to: 360    loops: QQ2.Animation.Infinite    running: true
}
QQ2.NumberAnimation {    duration: 100    loops: QQ2.Animation.Infinite    target: wheelanimation    property: "carspeed"    from: 0.0    to: 3000    running: true
}
ThanksRamy



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