Orillusion

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拾取事件 ​

在三维应用中时常需要点击场景中的物体，引擎支持射线包围盒拾取和帧缓冲区拾取。

拾取支持的事件类型：

名称解释
PICK_OVER当触控点进入碰撞体范围时触发一次
PICK_OUT当触控点离开碰撞体范围时触发一次
PICK_CLICK当触控点在碰撞体范围内按下并松开，在松开时触发一次
PICK_MOVE当触控点在碰撞体范围内移动时触发
PICK_UP当触控点在碰撞体范围内松开时触发一次
PICK_DOWN当触控点在碰撞体范围内按下时触发一次

监听事件 ​

拾取事件依赖 ColliderComponent 组件，我们可以直接对 Object3D 进行 PointerEvent3D 事件监听。引擎统一封装了两种拾取类型的用法，可以通过简单配置进行切换

ts
//引擎启动前需要配置开启拾取和拾取类型
Engine3D.setting.pick.enable = true;
// Bound: 包围盒拾取, pixel: 帧缓冲区拾取
Engine3D.setting.pick.mode = `bound`; // or 'pixel'

await Engine3D.init()
// 拾取检测依赖 Collider 碰撞组件
let obj = Object3D();
obj.addComponent(ColliderComponent);

// 在节点上添加 PickEvent 事件监听，在回调函数可以获取到对应的事件
obj.addEventListener(PointerEvent3D.PICK_CLICK, onPick, this);

// 或者通过 view.pickFire 监听所有物体点击事件
view.pickFire.addEventListener(PointerEvent3D.PICK_CLICK, onPick, this);

//回调函数中获取到事件信息
function onPick(e: PointerEvent3D) {
    ...
}

包围盒拾取 ​

射线包围盒是一种常用的 CPU 计算拾取方法，需要计算 ColliderComponent 组件的 shape 和鼠标射线的交集，在物体数量不多的场景中性能较好，但是精度较差，因为包围盒往往不能够精准的表达物体的真实形状。

为了保持 cpu 性能，目前包围盒拾取只支持主动 pick 点击拾取，暂不支持 over/hover 状态拾取。

ts
import {Object3D, Collider, BoxColliderShape, Vector3} from '@orillusion/core';

let box = new Object3D();
let mr = box.addComponent(MeshRenderer);
// 设置 box geometry
mr.geometry = new BoxGeometry(1,1,1);
// 添加碰撞盒检测
let collider = box.addComponent(ColliderComponent);
// bound 模式需要手动设置碰撞盒样式和大小
// 拾取精度取决于 box.geometry 和 collider.shape 的匹配程度
collider.shape = new BoxColliderShape().setFromCenterAndSize(new Vector3(0, 0, 0), new Vector3(1, 1, 1));
  • 左面的 box 使用同形状的 BoxColliderShape 进行检测，精度较好
  • 右边的 sphere 也使用 BoxColliderShape，但可点击区域就会比实际模型要大，精度较差

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<
ts
import { Engine3D, Scene3D, Vector3, Object3D, AtmosphericComponent, Camera3D, View3D, LitMaterial, MeshRenderer, BoxColliderShape, ColliderComponent, BoxGeometry, ComponentBase, Color, PointerEvent3D, SphereGeometry, DirectLight } from '@orillusion/core'

class TouchDemo {
    scene: Scene3D

    cameraObj: Object3D

    camera: Camera3D

    constructor() {}

    async run() {
        console.log('start demo')
        // enable pick and use bound mode
        Engine3D.setting.pick.enable = true
        Engine3D.setting.pick.mode = `bound`

        await Engine3D.init()

        this.scene = new Scene3D()
        this.scene.addComponent(AtmosphericComponent)
        this.cameraObj = new Object3D()
        this.camera = this.cameraObj.addComponent(Camera3D)
        this.scene.addChild(this.cameraObj)
        this.camera.lookAt(new Vector3(0, 0, 10), new Vector3(0, 0, 0))
        this.camera.perspective(60, Engine3D.aspect, 1, 10000.0)

        // add a base light
        let lightObj = new Object3D()
        lightObj.addComponent(DirectLight)
        this.scene.addChild(lightObj)

        let box = this.createBox(-2, 0, 0)
        let sphere = this.createSphere(2, 0, 0)

        let view = new View3D()
        view.scene = this.scene
        view.camera = this.camera
        // start render
        Engine3D.startRenderView(view)

        // listen all pick_click events
        view.pickFire.addEventListener(PointerEvent3D.PICK_CLICK, this.onPick, this)
    }

    createBox(x: number, y: number, z: number) {
        let boxObj = new Object3D()
        boxObj.transform.localPosition = new Vector3(x, y, z)

        let size: number = 2
        let shape: BoxColliderShape = new BoxColliderShape().setFromCenterAndSize(new Vector3(0, 0, 0), new Vector3(size, size, size))
        // add a box collider
        let collider = boxObj.addComponent(ColliderComponent)
        collider.shape = shape
        let mr: MeshRenderer = boxObj.addComponent(MeshRenderer)
        mr.geometry = new BoxGeometry(size, size, size)
        mr.material = new LitMaterial()
        this.scene.addChild(boxObj)
        return boxObj
    }

    createSphere(x: number, y: number, z: number) {
        let sphereObj = new Object3D()
        sphereObj.transform.localPosition = new Vector3(x, y, z)

        let size: number = 2
        let shape: BoxColliderShape = new BoxColliderShape().setFromCenterAndSize(new Vector3(0, 0, 0), new Vector3(size, size, size))
        // add a box collider
        let collider = sphereObj.addComponent(ColliderComponent)
        collider.shape = shape
        let mr: MeshRenderer = sphereObj.addComponent(MeshRenderer)
        mr.geometry = new SphereGeometry(size / 2, 20, 20)
        mr.material = new LitMaterial()
        this.scene.addChild(sphereObj)
        return sphereObj
    }

    onPick(e: PointerEvent3D) {
        console.log('onClick:', e)
        let mr: MeshRenderer = e.target.getComponent(MeshRenderer)
        mr.material.baseColor = Color.random()
    }
}
new TouchDemo().run()

帧缓冲拾取 ​

pixel 模式和 bound 模式不同，帧缓冲拾取 利用的是 GPU 的像素检测，几乎不消耗 CPU 性能，可以无视场景中交互对象的数量和形状复杂度，支持所有触控事件。当场景模型形状复杂或物体数量众多的时候，我们推荐使用 pixel 模式进行拾取检测。

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<
ts
import { AtmosphericComponent, BoxColliderShape, Camera3D, CameraUtil, ColliderComponent, Color, View3D, DirectLight, Engine3D, LitMaterial, HoverCameraController, KelvinUtil, MeshRenderer, Object3D, PointerEvent3D, Scene3D, SphereGeometry, Vector3 } from '@orillusion/core'

class Sample_MousePick {
    lightObj: Object3D
    cameraObj: Camera3D
    scene: Scene3D
    hover: HoverCameraController

    constructor() {}

    async run() {
        // enable pick and use pixel mode
        Engine3D.setting.pick.enable = true
        Engine3D.setting.pick.mode = `pixel`

        await Engine3D.init({})

        this.scene = new Scene3D()
        this.scene.addComponent(AtmosphericComponent)
        let camera = CameraUtil.createCamera3DObject(this.scene)
        camera.perspective(60, Engine3D.aspect, 1, 5000.0)

        this.hover = camera.object3D.addComponent(HoverCameraController)
        this.hover.setCamera(-30, -15, 120)

        let wukong = await Engine3D.res.loadGltf('https://cdn.orillusion.com/gltfs/wukong/wukong.gltf')
        wukong.transform.y = 30
        wukong.transform.scaleX = 20
        wukong.transform.scaleY = 20
        wukong.transform.scaleZ = 20
        wukong.forChild((node) => {
            if (node.hasComponent(MeshRenderer)) {
                node.addComponent(ColliderComponent)
            }
        })
        this.scene.addChild(wukong)

        this.initPickObject(this.scene)

        let view = new View3D()
        view.scene = this.scene
        view.camera = camera
        // start render
        Engine3D.startRenderView(view)

        // listen all mouse events
        view.pickFire.addEventListener(PointerEvent3D.PICK_UP, this.onUp, this)
        view.pickFire.addEventListener(PointerEvent3D.PICK_DOWN, this.onDow, this)
        view.pickFire.addEventListener(PointerEvent3D.PICK_CLICK, this.onPick, this)
        view.pickFire.addEventListener(PointerEvent3D.PICK_OVER, this.onOver, this)
        view.pickFire.addEventListener(PointerEvent3D.PICK_OUT, this.onOut, this)
        view.pickFire.addEventListener(PointerEvent3D.PICK_MOVE, this.onMove, this)
    }

    private initPickObject(scene: Scene3D): void {
        /******** light *******/
        {
            this.lightObj = new Object3D()
            this.lightObj.rotationX = 125
            this.lightObj.rotationY = 0
            this.lightObj.rotationZ = 40
            let lc = this.lightObj.addComponent(DirectLight)
            lc.lightColor = KelvinUtil.color_temperature_to_rgb(5355)
            lc.castShadow = true
            lc.intensity = 20
            scene.addChild(this.lightObj)
        }

        let size: number = 9
        let shape = new BoxColliderShape()
        shape.setFromCenterAndSize(new Vector3(), new Vector3(size, size, size))

        let geometry = new SphereGeometry(size / 2, 20, 20)
        for (let i = 0; i < 10; i++) {
            let obj = new Object3D()
            obj.name = 'sphere ' + i
            scene.addChild(obj)
            obj.x = (i - 5) * 10

            let mat = new LitMaterial()
            mat.emissiveMap = Engine3D.res.grayTexture
            mat.emissiveIntensity = 0.0

            let renderer = obj.addComponent(MeshRenderer)
            renderer.geometry = geometry
            renderer.material = mat
            obj.addComponent(ColliderComponent)
        }
    }

    private onUp(e: PointerEvent3D) {
        console.log('onUp', e.target.name, e.data.pickInfo)
        let obj = e.target as Object3D
        let mr = obj.getComponent(MeshRenderer)
        mr.material.baseColor = Color.random()
    }

    private onDow(e: PointerEvent3D) {
        console.log('onDown', e.target.name, e.data.pickInfo)
        let obj = e.target as Object3D
        let mr = obj.getComponent(MeshRenderer)
        mr.material.baseColor = Color.random()
    }

    private onPick(e: PointerEvent3D) {
        console.log('onPick', e.target.name, e.data.pickInfo)
        let obj = e.target as Object3D
        let mr = obj.getComponent(MeshRenderer)
        mr.material.baseColor = Color.random()
    }

    private onOver(e: PointerEvent3D) {
        console.log('onOver', e.target.name, e.data.pickInfo)
        let obj = e.target as Object3D
        let mr = obj.getComponent(MeshRenderer)
        mr.material.baseColor = Color.random()
    }

    private onOut(e: PointerEvent3D) {
        console.log('onOut', e.target.name, e.data.pickInfo)
        let obj = e.target as Object3D
        let mr = obj.getComponent(MeshRenderer)
        mr.material.baseColor = Color.random()
    }

    private onMove(e: PointerEvent3D) {
        console.log('onMove', e.target.name, e.data.pickInfo)
    }
}
new Sample_MousePick().run()