Qt Quick 3D - Particles 3D Testbed Example

 // Copyright (C) 2023 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

 pragma ComponentBehavior: Bound

 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: AppSettings.antialiasingMode
             antialiasingQuality: AppSettings.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: mainWindow.maxEmitterCount * 8 * mainWindow.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: mainWindow.maxEmitterCount * 8
                 color: "#ffffff"
             }
             ModelParticle3D {
                 id: particleRed
                 delegate: particleComponent
                 maxAmount: mainWindow.burstCount * 3
                 color: "#ff0000"
             }
             SpriteParticle3D {
                 id: particleSprite
                 sprite: Texture {
                     source: "images/star2.png"
                 }
                 maxAmount: mainWindow.maxEmitterCount * 8
                 color: "#ffff00"
                 particleScale: 30.0
             }
             SpriteParticle3D {
                 id: particleTrailSprite
                 sprite: Texture {
                     source: "images/star2.png"
                 }
                 maxAmount: mainWindow.maxEmitterCount * 8 * mainWindow.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: mainWindow.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: mainWindow.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(mainWindow.burstCount);
         }
     }

     SettingsView {
         Row {
             spacing: 10
             anchors.horizontalCenter: parent.horizontalCenter
             Button {
                 text: psystem.running ? qsTr("Stop") : qsTr("Start")
                 font.pointSize: AppSettings.fontSizeSmall
                 onClicked: {
                     psystem.running = !psystem.running;
                 }
             }
             Button {
                 text: psystem.paused ? qsTr("Continue") : qsTr("Pause")
                 font.pointSize: AppSettings.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: " + mainWindow.modelEmittersAmount
         }
         Item { width: 1; height: 5 }
         Row {
             spacing: 10
             anchors.horizontalCenter: parent.horizontalCenter
             Button {
                 text: qsTr("Add")
                 font.pointSize: AppSettings.fontSizeSmall
                 enabled: mainWindow.modelEmittersAmount < 10
                 onClicked: mainWindow.createModelEmitter();
             }
             Button {
                 text: qsTr("Remove")
                 font.pointSize: AppSettings.fontSizeSmall
                 enabled: mainWindow.modelEmittersAmount > 0
                 onClicked: {
                     let instance = mainWindow.modelEmitters.pop();
                     instance.destroy();
                     modelEmittersAmount = mainWindow.modelEmitters.length;
                 }
             }
         }
         Item { width: 1; height: 20 }
         CustomLabel {
             anchors.horizontalCenter: parent.horizontalCenter
             text: "Sprite Emitters: " + mainWindow.spriteEmittersAmount
         }
         Item { width: 1; height: 5 }
         Row {
             spacing: 10
             anchors.horizontalCenter: parent.horizontalCenter
             Button {
                 text: qsTr("Add")
                 font.pointSize: AppSettings.fontSizeSmall
                 enabled: mainWindow.spriteEmittersAmount < 10
                 onClicked: mainWindow.createSpriteEmitter();
             }
             Button {
                 text: qsTr("Remove")
                 font.pointSize: AppSettings.fontSizeSmall
                 enabled: mainWindow.spriteEmittersAmount > 0
                 onClicked: {
                     let instance = mainWindow.spriteEmitters.pop();
                     instance.destroy();
                     spriteEmittersAmount = mainWindow.spriteEmitters.length;
                 }
             }
         }

     }

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