Qt Quick 3D - Level of Detail Helper Example

 // Copyright (C) 2022 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

 import QtQuick
 import QtQuick3D
 import QtQuick3D.Helpers

 Window {
     id: window
     width: 1280
     height: 720
     visible: true

     View3D {
         id: view
         anchors.fill: parent

         environment: SceneEnvironment {
             clearColor: "black"
             backgroundMode: SceneEnvironment.Color
             antialiasingMode: SceneEnvironment.MSAA
             antialiasingQuality: SceneEnvironment.High
         }

         PerspectiveCamera {
             id: camera
             position: Qt.vector3d(0, 10, 300)
             clipNear: 1.0
             NumberAnimation on z {
                 from: 200
                 to: -100
                 duration: 40 * 1000
             }
         }

         DirectionalLight {
             eulerRotation.x: -30
             eulerRotation.y: -70
             ambientColor: Qt.rgba(0.5, 0.5, 0.5, 1.0)
         }

         RandomInstancing {
             id: randomInstancing
             instanceCount: 800

             position: InstanceRange {
                 from: Qt.vector3d(-200, 0, -200)
                 to: Qt.vector3d(200, 1, 200)
             }
             scale: InstanceRange {
                 from: Qt.vector3d(10, 10, 10)
                 to: Qt.vector3d(10, 10, 10)
             }
             rotation: InstanceRange {
                 from: Qt.vector3d(0, 0, 0)
                 to: Qt.vector3d(0, 0, 0)
             }
             color: InstanceRange {
                 from: "grey"
                 to: "white"
                 proportional: true
             }

             randomSeed: 2021
         }

         PrincipledMaterial {
             id: marbleMaterial
             baseColorMap: Texture {
                 source: "maps/baseColor.png"
                 generateMipmaps: true
                 mipFilter: Texture.Linear
             }
             opacityChannel: Material.A
             metalnessMap: Texture {
                 source: "maps/occlusionRoughnessMetallic.png"
                 generateMipmaps: true
                 mipFilter: Texture.Linear
             }
             metalnessChannel: Material.B
             roughnessMap: Texture {
                 source: "maps/occlusionRoughnessMetallic.png"
                 generateMipmaps: true
                 mipFilter: Texture.Linear
             }
             roughnessChannel: Material.G
             metalness: 1
             roughness: 1
             normalMap: Texture {
                 source: "maps/normal.png"
                 generateMipmaps: true
                 mipFilter: Texture.Linear
             }
         }

         LodManager {
             camera: camera
             distances: [100, 140, 180]
             fadeDistance: 10

             Model {
                 scale: Qt.vector3d(100, 100, 100);
                 source: "meshes/marble_bust_01_LOD_0.mesh"
                 materials: [ marbleMaterial ]
             }

             Model {
                 scale: Qt.vector3d(100, 100, 100);
                 source: "meshes/marble_bust_01_LOD_1.mesh"
                 materials: [ marbleMaterial ]
             }

             Model {
                 scale: Qt.vector3d(100, 100, 100);
                 source: "meshes/marble_bust_01_LOD_2.mesh"
                 materials: [ marbleMaterial ]
             }

             Model {
                 scale: Qt.vector3d(100, 100, 100);
                 source: "meshes/marble_bust_01_LOD_3.mesh"
                 materials: [ marbleMaterial ]
             }
         }

         LodManager {
             camera: camera
             distances: [50, 100, 150]

             Model {
                 instancing: randomInstancing
                 source: "#Sphere"
                 materials: [
                     PrincipledMaterial {
                         metalness: 0
                         roughness: 1
                         baseColor: "red"
                     }
                 ]
                 scale: Qt.vector3d(0.005, 0.005, 0.005)
             }

             Model {
                 instancing: randomInstancing
                 source: "#Cylinder"
                 materials: [
                     PrincipledMaterial {
                         metalness: 0
                         roughness: 1
                         baseColor: "orange"
                     }
                 ]
                 scale: Qt.vector3d(0.005, 0.005, 0.005)
             }

             Model {
                 instancing: randomInstancing
                 source: "#Cube"
                 materials: [
                     PrincipledMaterial {
                         metalness: 0
                         roughness: 1
                         baseColor: "yellow"
                     }
                 ]
                 scale: Qt.vector3d(0.005, 0.005, 0.005)
             }

             Model {
                 instancing: randomInstancing
                 source: "#Rectangle"
                 materials: [
                     PrincipledMaterial {
                         metalness: 0
                         roughness: 1
                         baseColor: "green"
                     }
                 ]
                 scale: Qt.vector3d(0.005, 0.005, 0.005)
             }
         }
     }

     DebugView {
         source: view
     }
 }