Qt Quick 3D - Particles 3D Testbed Example

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

 import QtQuick
 import QtQuick3D
 import QtQuick3D.Particles3D

 Item {
     id: mainWindow

     readonly property real meterTicksAngle: 300
     readonly property bool particleNeedle: checkBoxParticlesNeedle.checked
     property real separation: sliderElementSeparation.sliderValue

     anchors.fill: parent

     Behavior on separation {
         SmoothedAnimation {
             velocity: 0.2
             duration: 1000
         }
     }

     View3D {
         id: view3D
         anchors.fill: parent

         environment: SceneEnvironment {
             clearColor: "#161610"
             backgroundMode: SceneEnvironment.Color
             antialiasingMode: AppSettings.antialiasingMode
             antialiasingQuality: AppSettings.antialiasingQuality
         }

         PerspectiveCamera {
             position: Qt.vector3d(0, 100, 600 - mainWindow.separation * 100)
         }

         PointLight {
             position: Qt.vector3d(200, 400, 300)
             brightness: 5
             ambientColor: Qt.rgba(0.3, 0.3, 0.3, 1.0)
         }

         // Background
         Model {
             source: "#Rectangle"
             scale: Qt.vector3d(25, 15, 0)
             z: -300
             materials: PrincipledMaterial {
                 baseColor: "#505040"
             }
         }

         Node {
             id: speedometerComponent

             position: Qt.vector3d(0, 100, 0)
             eulerRotation.x: 90 - mainWindow.separation * 75

             // Light which follows the needle
             PointLight {
                 // Calculates the direction of the needle
                 function getNeedleAngle(startAngle) {
                     return Math.sin(startAngle +
                                     (-(180 / 360) +
                                      (-gaugeItem.value * mainWindow.meterTicksAngle / 360) +
                                      (mainWindow.meterTicksAngle / 2 + 180) / 360) * 2 * Math.PI);
                 }

                 readonly property real lightRadius: 120
                 readonly property real posX: getNeedleAngle(Math.PI) * lightRadius
                 readonly property real posY: getNeedleAngle(Math.PI / 2) * lightRadius

                 position: Qt.vector3d(posX, 40, -posY)
                 color: Qt.rgba(1.0, 0.8, 0.4, 1.0)
                 brightness: sliderNeedleBrightness.sliderValue
                 quadraticFade: 4.0
             }

             Model {
                 y: -4 - mainWindow.separation * 100
                 source: "meshes/meter_background.mesh"
                 scale: Qt.vector3d(30, 30, 30)
                 materials: PrincipledMaterial {
                     baseColor: "#505050"
                     metalness: 1.0
                     roughness: 0.6
                     normalMap: Texture {
                         source: "images/leather_n.png"
                     }
                     normalStrength: 0.4
                 }
             }
             Model {
                 y: -35 - mainWindow.separation * 100
                 source: "#Sphere"
                 scale: Qt.vector3d(1.6, 0.2, 1.6)
                 materials: PrincipledMaterial {
                     baseColor: "#606060"
                 }
             }
             Model {
                 y: -mainWindow.separation * 60
                 source: "#Cylinder"
                 scale: Qt.vector3d(0.2, 0.8, 0.2)
                 materials: PrincipledMaterial {
                     baseColor: "#606060"
                 }
             }
             Model {
                 y: 30 - mainWindow.separation * 60
                 source: "#Sphere"
                 scale: Qt.vector3d(0.4, 0.1, 0.4)
                 materials: PrincipledMaterial {
                     baseColor: "#f0f0f0"
                 }
             }

             // Speedometer labels
             Model {
                 y: 25 + mainWindow.separation * 20
                 source: "#Rectangle"
                 scale: Qt.vector3d(4, 4, 4)
                 eulerRotation.x: -90
                 materials: PrincipledMaterial {
                     alphaMode: PrincipledMaterial.Blend
                     baseColorMap: Texture {
                         source: "images/speedometer_labels.png"
                     }
                 }
             }

             Model {
                 y: mainWindow.separation * 60
                 source: "meshes/meter_edge.mesh"
                 scale: Qt.vector3d(30, 30, 30)
                 materials: PrincipledMaterial {
                     baseColor: "#b0b0b0"
                 }
             }

             Node {
                 id: gaugeItem

                 property real value: 0
                 property real needleSize: 180

                 SequentialAnimation {
                     running: checkBoxAnimateSpeed.checked
                     loops: Animation.Infinite
                     NumberAnimation {
                         target: gaugeItem
                         property: "value"
                         duration: 8000
                         to: 1
                         easing.type: Easing.InOutQuad
                     }
                     NumberAnimation {
                         target: gaugeItem
                         property: "value"
                         duration: 8000
                         to: 0
                         easing.type: Easing.InOutQuad
                     }
                 }

                 y: 20 - mainWindow.separation * 60
                 eulerRotation.z: 90
                 eulerRotation.y: -mainWindow.meterTicksAngle * value + (mainWindow.meterTicksAngle/2 - 90)

                 Model {
                     position.y: gaugeItem.needleSize / 2
                     source: "#Cylinder"
                     scale: Qt.vector3d(0.05, gaugeItem.needleSize * 0.01, 0.2)
                     materials: PrincipledMaterial {
                         baseColor: "#606060"
                         opacity: mainWindow.particleNeedle ? 0.0 : 1.0
                     }

                     ParticleEmitter3D {
                         system: psystemGauge
                         particle: particleSpark
                         y: 10
                         scale: Qt.vector3d(0.1, 0.8, 0.1)
                         shape: ParticleShape3D {
                             type: ParticleShape3D.Cube
                         }
                         particleScale: 2.0
                         particleScaleVariation: 1.0
                         particleRotationVariation: Qt.vector3d(0, 0, 180)
                         particleRotationVelocityVariation: Qt.vector3d(20, 20, 200);
                         emitRate: 500
                         lifeSpan: 2000
                         lifeSpanVariation: 1000
                     }

                     // Needle particle system
                     // This system rotates together with the needle
                     ParticleSystem3D {
                         id: psystemNeedle
                         running: mainWindow.particleNeedle
                         visible: running
                         SpriteParticle3D {
                             id: needleParticle
                             sprite: Texture {
                                 source: "images/dot.png"
                             }
                             maxAmount: 500
                             fadeInDuration: 50
                             fadeOutDuration: 200
                             color: "#40808020"
                             colorVariation: Qt.vector4d(0.2, 0.2, 0.0, 0.2)
                             blendMode: SpriteParticle3D.Screen
                         }

                         ParticleEmitter3D {
                             particle: needleParticle
                             y: -50
                             scale: Qt.vector3d(0.2, 0.0, 0.2)
                             shape: ParticleShape3D {
                                 type: ParticleShape3D.Cube
                             }

                             particleScale: 4.0
                             particleScaleVariation: 2.0
                             particleEndScale: 1.0
                             particleEndScaleVariation: 0.5
                             velocity: VectorDirection3D {
                                 direction: Qt.vector3d(0, 110, 0)
                                 directionVariation: Qt.vector3d(10, 10, 10)
                             }
                             emitRate: sliderNeedleEmitrate.sliderValue
                             lifeSpan: 1000
                         }
                     }
                 }
             }
             // Gauge particle system
             ParticleSystem3D {
                 id: psystemGauge
                 // Particles coming under the needle
                 SpriteParticle3D {
                     id: particleSpark
                     sprite: Texture {
                         source: "images/star3.png"
                     }
                     maxAmount: 1500
                     fadeInEffect: SpriteParticle3D.FadeNone
                     fadeOutDuration: 200
                     color: "#40ff0000"
                     colorVariation: Qt.vector4d(0.4, 0.2, 0.2, 0.2)
                     unifiedColorVariation: true
                     blendMode: SpriteParticle3D.Screen
                 }
                 // Particles rotating the gauge
                 SpriteParticle3D {
                     id: particleSpark2
                     sprite: Texture {
                         source: "images/star3.png"
                     }
                     maxAmount: 30
                     fadeInDuration: 1000
                     fadeOutDuration: 1000
                     color: "#20ffffff"
                     colorVariation: Qt.vector4d(0.2, 0.2, 0.5, 0.1)
                     blendMode: SpriteParticle3D.Screen
                 }
                 ParticleEmitter3D {
                     y: 40 + mainWindow.separation * 60
                     particle: particleSpark2
                     scale: Qt.vector3d(3.8, 0, 3.8)
                     shape: ParticleShape3D {
                         type: ParticleShape3D.Cylinder
                     }
                     emitRate: 10
                     lifeSpan: 3000
                     particleScale: 4.0
                     particleScaleVariation: 3.0
                     particleRotationVariation: Qt.vector3d(20, 20, 180)
                     particleRotationVelocityVariation: Qt.vector3d(10, 10, 50)
                 }
                 Wander3D {
                     uniqueAmount: Qt.vector3d(10, 0, 10)
                     uniquePace: Qt.vector3d(0.1, 0.1, 0.1)
                     fadeInDuration: 2000
                 }
                 PointRotator3D {
                     particles: [ particleSpark2 ]
                     magnitude: -20
                 }
             }
         }
     }

     SettingsView {
         CustomCheckBox {
             id: checkBoxAnimateSpeed
             text: "Animate Speed"
             checked: true
         }
         CustomLabel {
             text: "Speed"
             opacity: !checkBoxAnimateSpeed.checked ? 1.0 : 0.4
         }
         CustomSlider {
             id: sliderSpeedValue
             sliderValue: gaugeItem.value
             sliderEnabled: !checkBoxAnimateSpeed.checked
             fromValue: 0
             toValue: 1
             onSliderValueChanged: gaugeItem.value = sliderValue;
         }
         CustomCheckBox {
             id: checkBoxParticlesNeedle
             text: "Particles Needle"
             checked: true
         }
         CustomLabel {
             text: "Needle emitRate"
             opacity: checkBoxParticlesNeedle.checked ? 1.0 : 0.4
         }
         CustomSlider {
             id: sliderNeedleEmitrate
             sliderValue: 200
             sliderEnabled: checkBoxParticlesNeedle.checked
             fromValue: 50
             toValue: 500
         }
         CustomLabel {
             text: "Needle Brightness"
         }
         CustomSlider {
             id: sliderNeedleBrightness
             sliderValue: 10
             fromValue: 0
             toValue: 50
         }
         CustomLabel {
             text: "Elements Separation"
         }
         CustomSlider {
             id: sliderElementSeparation
             sliderValue: 0
             fromValue: 0
             toValue: 1
         }
     }

     LoggingView {
         anchors.bottom: parent.bottom
         particleSystems: [psystemGauge, psystemNeedle]
     }
 }