- Qt 6.5
- Qt Quick 3D
- Qt Quick 3D Examples and Tutorials
- Qt Quick 3D - Particles 3D Testbed Example
- Qt Quick 3D | Commercial or GPLv3

# Qt Quick 3D - Particles 3D Testbed Example

     // Copyright (C) 2021 The Qt Company Ltd.
     // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

     import QtQuick
     import QtQuick3D
     import QtQuick3D.Particles3D
     import QtQuick.Controls

     Item {
         id: mainWindow

         readonly property int burstCount: 300
         readonly property int maxEmitterCount: 10
         readonly property int trailEmitRate: 10

         property var modelEmitters: []
         property int modelEmittersAmount: 0
         property var spriteEmitters: []
         property int spriteEmittersAmount: 0

         function createModelEmitter() {
             var newObject = modelEmitterComponent.createObject(psystem);
             modelEmitters.push(newObject);
             modelEmittersAmount = modelEmitters.length;
         }

         function createSpriteEmitter() {
             var newObject = spriteEmitterComponent.createObject(psystem);
             spriteEmitters.push(newObject);
             spriteEmittersAmount = spriteEmitters.length;
         }

         anchors.fill: parent
         Component.onCompleted: {
             createModelEmitter();
             createSpriteEmitter();
         }

         View3D {
             id: view3D
             anchors.fill: parent
             camera: camera

             environment: SceneEnvironment {
                 clearColor: "#202020"
                 backgroundMode: SceneEnvironment.Color
                 antialiasingMode: settings.antialiasingMode
                 antialiasingQuality: settings.antialiasingQuality
             }

             PerspectiveCamera {
                 id: camera
                 position: Qt.vector3d(0, 100, 600)
             }

             PointLight {
                 position: Qt.vector3d(0, 400, 100)
                 brightness: 10
                 ambientColor: Qt.rgba(0.3, 0.3, 0.3, 1.0)
             }

             // Model shared between particles
             Component {
                 id: particleComponent
                 Model {
                     source: "#Cube"
                     scale: Qt.vector3d(0.2, 0.2, 0.2)
                     materials: DefaultMaterial {
                     }
                 }
             }

             Component {
                 id: modelEmitterComponent
                 Model {
                     source: "#Cylinder"
                     materials: DefaultMaterial {}
                     position: Qt.vector3d(Math.random() * 250 - 300, -150, 0)
                     scale: Qt.vector3d(0.5, 0.1, 0.5)
                     ParticleEmitter3D {
                         system: psystem
                         particle: particleWhite
                         particleScaleVariation: 0.4
                         particleRotationVariation: Qt.vector3d(180, 180, 180)
                         particleRotationVelocityVariation: Qt.vector3d(200, 200, 200);
                         velocity: VectorDirection3D {
                             direction: Qt.vector3d(0, 400, 0)
                             directionVariation: Qt.vector3d(40, 40, 0)
                         }
                         emitRate: 2
                         lifeSpan: 4000
                     }
                 }
             }

             Component {
                 id: spriteEmitterComponent
                 Model {
                     source: "#Cylinder"
                     materials: DefaultMaterial { diffuseColor: "#ffff00" }
                     position: Qt.vector3d(Math.random() * 250 + 50, -150, 0)
                     scale: Qt.vector3d(0.5, 0.1, 0.5)
                     ParticleEmitter3D {
                         system: psystem
                         particle: particleSprite
                         particleScaleVariation: 0.4
                         particleRotationVariation: Qt.vector3d(180, 180, 180)
                         particleRotationVelocityVariation: Qt.vector3d(200, 200, 200);
                         velocity: VectorDirection3D {
                             direction: Qt.vector3d(0, 400, 0)
                             directionVariation: Qt.vector3d(40, 40, 0)
                         }
                         emitRate: 2
                         lifeSpan: 4000
                     }
                 }
             }

             ParticleSystem3D {
                 id: psystem

                 useRandomSeed: checkBoxRandomize.checked

                 onTimeChanged: {
                     if (time > 9500)
                         psystem.paused = true;
                 }

                 // Particles
                 ModelParticle3D {
                     id: particleTrailModel
                     delegate: particleComponent
                     maxAmount: maxEmitterCount * 8 * trailEmitRate
                     fadeInDuration: 200
                     fadeOutDuration: 500
                     color: "#808080"
                     colorVariation: Qt.vector4d(0.2, 0.2, 0.2, 0.5)
                     unifiedColorVariation: true
                 }
                 ModelParticle3D {
                     id: particleWhite
                     delegate: particleComponent
                     maxAmount: maxEmitterCount * 8
                     color: "#ffffff"
                 }
                 ModelParticle3D {
                     id: particleRed
                     delegate: particleComponent
                     maxAmount: burstCount * 3
                     color: "#ff0000"
                 }
                 SpriteParticle3D {
                     id: particleSprite
                     sprite: Texture {
                         source: "images/star2.png"
                     }
                     maxAmount: maxEmitterCount * 8
                     color: "#ffff00"
                     particleScale: 30.0
                 }
                 SpriteParticle3D {
                     id: particleTrailSprite
                     sprite: Texture {
                         source: "images/star2.png"
                     }
                     maxAmount: maxEmitterCount * 8 * trailEmitRate
                     fadeInDuration: 200
                     fadeOutDuration: 500
                     color: "#999900"
                     particleScale: 15.0
                 }

                 // Emitters, one per particle
                 TrailEmitter3D {
                     id: modelTrailEmitter
                     particle: particleTrailModel
                     follow: particleWhite
                     particleScale: 0.5
                     particleScaleVariation: 0.2
                     particleRotationVariation: Qt.vector3d(180, 180, 180)
                     particleRotationVelocityVariation: Qt.vector3d(100, 100, 100);
                     velocity: VectorDirection3D {
                         directionVariation: Qt.vector3d(20, 20, 20)
                     }
                     emitRate: trailEmitRate
                     lifeSpan: 1000
                 }
                 TrailEmitter3D {
                     id: spriteTrailEmitter
                     particle: particleTrailSprite
                     follow: particleSprite
                     particleScaleVariation: 0.2
                     particleRotationVariation: Qt.vector3d(180, 180, 180)
                     particleRotationVelocityVariation: Qt.vector3d(100, 100, 100);
                     velocity: VectorDirection3D {
                         directionVariation: Qt.vector3d(20, 20, 20)
                     }
                     emitRate: trailEmitRate
                     lifeSpan: 1000
                 }

                 ParticleEmitter3D {
                     id: burstEmitter
                     particle: particleRed
                     scale: Qt.vector3d(0.5, 0.5, 0.5)
                     particleScale: 0.2
                     particleEndScale: 0.4
                     particleRotationVariation: Qt.vector3d(180, 180, 180)
                     particleRotationVelocityVariation: Qt.vector3d(200, 200, 200);
                     shape: ParticleShape3D {
                         type: ParticleShape3D.Sphere
                         fill: false
                     }
                     velocity: TargetDirection3D {
                         position: burstEmitter.position
                         magnitude: -4.0
                     }
                     lifeSpan: 1000
                     lifeSpanVariation: 500
                 }

                 Gravity3D {
                     direction: Qt.vector3d(0, 1, 0)
                     magnitude: -200
                 }
             }
         }

         MouseArea {
             anchors.fill: parent
             onClicked: {
                 var pos = view3D.mapTo3DScene(Qt.vector3d(mouseX, mouseY, camera.z));
                 burstEmitter.setPosition(pos);
                 burstEmitter.burst(burstCount);
             }
         }

         SettingsView {
             Row {
                 spacing: 10
                 anchors.horizontalCenter: parent.horizontalCenter
                 Button {
                     text: psystem.running ? qsTr("Stop") : qsTr("Start")
                     font.pointSize: settings.fontSizeSmall
                     onClicked: {
                         psystem.running = !psystem.running;
                     }
                 }
                 Button {
                     text: psystem.paused ? qsTr("Continue") : qsTr("Pause")
                     font.pointSize: settings.fontSizeSmall
                     enabled: psystem.running
                     onClicked: {
                         psystem.paused = !psystem.paused;
                     }
                 }
             }
             Item {
                 width: 1
                 height: 10
             }
             CustomLabel {
                 text: "ParticleSystem time"
                 opacity: timeSlider.sliderEnabled ? 1.0 : 0.4
             }
             CustomSlider {
                 id: timeSlider
                 sliderValue: psystem.time
                 sliderEnabled: psystem.paused
                 fromValue: 0
                 toValue: 10000
                 onSliderValueChanged: psystem.setTime(sliderValue);
             }
             Item {
                 width: 1
                 height: 10
             }
             CustomLabel {
                 text: "ParticleSystem seed: " + psystem.seed
             }
             CustomCheckBox {
                 id: checkBoxRandomize
                 text: "Use random seed"
                 checked: true
             }
             CustomLabel {
                 text: "Custom seed"
                 opacity: psystem.useRandomSeed ? 0.4 : 1.0
             }
             CustomSlider {
                 sliderValue: 0
                 sliderEnabled: !psystem.useRandomSeed
                 fromValue: 0
                 toValue: 99
                 sliderStepSize: 1
                 onSliderValueChanged: psystem.setSeed(sliderValue);
             }
             Item { width: 1; height: 20 }
             CustomLabel {
                 anchors.horizontalCenter: parent.horizontalCenter
                 text: "Model Emitters: " + modelEmittersAmount
             }
             Item { width: 1; height: 5 }
             Row {
                 spacing: 10
                 anchors.horizontalCenter: parent.horizontalCenter
                 Button {
                     text: qsTr("Add")
                     font.pointSize: settings.fontSizeSmall
                     enabled: modelEmittersAmount < 10
                     onClicked: createModelEmitter();
                 }
                 Button {
                     text: qsTr("Remove")
                     font.pointSize: settings.fontSizeSmall
                     enabled: modelEmittersAmount > 0
                     onClicked: {
                         let instance = modelEmitters.pop();
                         instance.destroy();
                         modelEmittersAmount = modelEmitters.length;
                     }
                 }
             }
             Item { width: 1; height: 20 }
             CustomLabel {
                 anchors.horizontalCenter: parent.horizontalCenter
                 text: "Sprite Emitters: " + spriteEmittersAmount
             }
             Item { width: 1; height: 5 }
             Row {
                 spacing: 10
                 anchors.horizontalCenter: parent.horizontalCenter
                 Button {
                     text: qsTr("Add")
                     font.pointSize: settings.fontSizeSmall
                     enabled: spriteEmittersAmount < 10
                     onClicked: createSpriteEmitter();
                 }
                 Button {
                     text: qsTr("Remove")
                     font.pointSize: settings.fontSizeSmall
                     enabled: spriteEmittersAmount > 0
                     onClicked: {
                         let instance = spriteEmitters.pop();
                         instance.destroy();
                         spriteEmittersAmount = spriteEmitters.length;
                     }
                 }
             }

         }

         LoggingView {
             anchors.bottom: parent.bottom
             particleSystems: [psystem]
         }
     }