Raycaster

Video Lecture

Raycaster Raycaster

Description

Raycasting allows you to create a vector from a 3D point in the scene, and detect which object(s) the vector intersects.

The raycasting class is almost always used for mouse picking objects in the 3D scene.

We can setup the raycaster position and direction using the set or setFromCamera methods and then call its intersectObject or intersectObjects methods to tell us many things about the scene objects that were intersected by the ray, including,

  • the distance of the intersect from the raycaster position,
  • the position of the intersection in the 3D scene,
  • the face of the object that was intersected,
  • the direction of the faces normal,
  • the UV coordinate of the intersect on the face
  • and a reference to the intersected object itself.

Start Code

./src/server/server.ts

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import express from "express"
import path from "path"
import http from "http"

const port: number = 3000

class App {
    private server: http.Server
    private port: number

    constructor(port: number) {
        this.port = port
        const app = express()
        app.use(express.static(path.join(__dirname, '../client')))
        app.use('/build/three.module.js', express.static(path.join(__dirname, '../../node_modules/three/build/three.module.js')))
        app.use('/jsm/controls/OrbitControls', express.static(path.join(__dirname, '../../node_modules/three/examples/jsm/controls/OrbitControls.js')))
        app.use('/jsm/loaders/GLTFLoader', express.static(path.join(__dirname, '../../node_modules/three/examples/jsm/loaders/GLTFLoader.js')))
        app.use('/jsm/libs/stats.module', express.static(path.join(__dirname, '../../node_modules/three/examples/jsm/libs/stats.module.js')))

        this.server = new http.Server(app);
    }

    public Start() {
        this.server.listen(this.port, () => {
            console.log( `Server listening on port ${this.port}.` )
        })
    }
}

new App(port).Start()

./src/client/client.ts

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import * as THREE from '/build/three.module.js'
import { OrbitControls } from '/jsm/controls/OrbitControls'
import { GLTFLoader } from '/jsm/loaders/GLTFLoader'
import Stats from '/jsm/libs/stats.module'

const scene: THREE.Scene = new THREE.Scene()
const axesHelper = new THREE.AxesHelper(5)
scene.add(axesHelper)

const camera: THREE.PerspectiveCamera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000)
camera.position.z = 2

const renderer: THREE.WebGLRenderer = new THREE.WebGLRenderer()
renderer.physicallyCorrectLights = true
renderer.shadowMap.enabled = true
renderer.outputEncoding = THREE.sRGBEncoding
renderer.setSize(window.innerWidth, window.innerHeight)
document.body.appendChild(renderer.domElement)

const controls = new OrbitControls(camera, renderer.domElement)

// const material = new THREE.LineBasicMaterial({ color: 0xff0000 });
// const points = [];
// points.push( new THREE.Vector3( 0, 0, 0 ) );
// points.push( new THREE.Vector3( 0, 0, .25 ) );
// const geometry = new THREE.BufferGeometry().setFromPoints( points );
// const line = new THREE.Line( geometry, material );
// scene.add( line );

// var arrowHelper = new THREE.ArrowHelper(
//     new THREE.Vector3(),
//     new THREE.Vector3(),
//     .25,
//     0xffff00);
// scene.add(arrowHelper);

// const material: THREE.MeshNormalMaterial = new THREE.MeshNormalMaterial()

// const boxGeometry: THREE.BoxGeometry = new THREE.BoxGeometry(.2, .2, .2)
// const coneGeometry = new THREE.ConeGeometry(.05, .2, 8);

// const raycaster = new THREE.Raycaster();
// const sceneMeshes = []

const loader = new GLTFLoader()
loader.load(
    'models/monkey_textured.glb',
    function (gltf) {
        gltf.scene.traverse(function (child) {
            if ((<THREE.Mesh>child).isMesh) {
                let m = <THREE.Mesh>child
                m.receiveShadow = true
                m.castShadow = true;
                //(<THREE.MeshStandardMaterial>m.material).flatShading = true
                //sceneMeshes.push(m)
            }
            if ((<THREE.Light>child).isLight) {
                let l = <THREE.Light>child
                l.castShadow = true
                l.shadow.bias = -.003
                l.shadow.mapSize.width = 2048
                l.shadow.mapSize.height = 2048
            }
        })
        scene.add(gltf.scene);
        //sceneMeshes.push(gltf.scene)
    },
    (xhr) => {
        console.log((xhr.loaded / xhr.total * 100) + '% loaded')
    },
    (error) => {
        console.log(error);
    }
);

window.addEventListener('resize', onWindowResize, false)
function onWindowResize() {
    camera.aspect = window.innerWidth / window.innerHeight
    camera.updateProjectionMatrix()
    renderer.setSize(window.innerWidth, window.innerHeight)
    render()
}

// renderer.domElement.addEventListener('dblclick', onDoubleClick, false);
// renderer.domElement.addEventListener('mousemove', onMouseMove, false);



// function onMouseMove(event) {
//     const mouse = {
//         x: (event.clientX / renderer.domElement.clientWidth) * 2 - 1,
//         y: -(event.clientY / renderer.domElement.clientHeight) * 2 + 1
//     }
//     console.log(mouse)
//
//     // raycaster.setFromCamera(mouse, camera);

//     // const intersects = raycaster.intersectObjects(sceneMeshes, false);

//     // if (intersects.length > 0) {
//     //     //console.log(sceneMeshes.length + " " + intersects.length)
//     //     //console.log(intersects[0])
//     //     //console.log(intersects[0].object.userData.name + " " + intersects[0].distance + " ")
//     //     //console.log(intersects[0].face.normal)
//     //     // line.position.set(0, 0, 0);
//     //     // line.lookAt(intersects[0].face.normal);
//     //     // line.position.copy(intersects[0].point);


//     //     // let n = new THREE.Vector3();
//     //     // n.copy(intersects[0].face.normal);
//     //     // n.transformDirection(intersects[0].object.matrixWorld);

//     //     // arrowHelper.setDirection(n);
//     //     // arrowHelper.position.copy(intersects[0].point);
//     // }
// }


// function onDoubleClick(event) {
//     const mouse = {
//         x: (event.clientX / renderer.domElement.clientWidth) * 2 - 1,
//         y: -(event.clientY / renderer.domElement.clientHeight) * 2 + 1
//     }
//     raycaster.setFromCamera(mouse, camera);

//     const intersects = raycaster.intersectObjects(sceneMeshes, false);

//     if (intersects.length > 0) {

//         let n = new THREE.Vector3();
//         n.copy(intersects[0].face.normal);
//         n.transformDirection(intersects[0].object.matrixWorld);

//         const cube: THREE.Mesh = new THREE.Mesh(boxGeometry, material)
//         //const cube: THREE.Mesh = new THREE.Mesh(coneGeometry, material)

//         cube.lookAt(n);
//         //cube.rotateX(Math.PI / 2)
//         cube.position.copy(intersects[0].point);
//         //cube.position.addScaledVector(n, .1)

//         scene.add(cube)
//         //sceneMeshes.push(cube)
//     }
// }

const stats = Stats()
document.body.appendChild(stats.dom)

var animate = function () {
    requestAnimationFrame(animate)

    controls.update()

    // if (sceneMeshes.length > 1) {
    //     sceneMeshes[1].rotation.x += .002
    // }

    render()

    stats.update()
};

function render() {
    renderer.render(scene, camera)
}
animate();

Final Script

./src/client/client.ts

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import * as THREE from '/build/three.module.js'
import { OrbitControls } from '/jsm/controls/OrbitControls'
import { GLTFLoader } from '/jsm/loaders/GLTFLoader'
import Stats from '/jsm/libs/stats.module'

const scene: THREE.Scene = new THREE.Scene()
const axesHelper = new THREE.AxesHelper(5)
scene.add(axesHelper)

const camera: THREE.PerspectiveCamera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000)
camera.position.z = 2

const renderer: THREE.WebGLRenderer = new THREE.WebGLRenderer()
renderer.physicallyCorrectLights = true
renderer.shadowMap.enabled = true
renderer.outputEncoding = THREE.sRGBEncoding
renderer.setSize(window.innerWidth, window.innerHeight)
document.body.appendChild(renderer.domElement)

const controls = new OrbitControls(camera, renderer.domElement)

// const material = new THREE.LineBasicMaterial({ color: 0xff0000 });
// const points = [];
// points.push( new THREE.Vector3( 0, 0, 0 ) );
// points.push( new THREE.Vector3( 0, 0, .25 ) );
// const geometry = new THREE.BufferGeometry().setFromPoints( points );
// const line = new THREE.Line( geometry, material );
// scene.add( line );

var arrowHelper = new THREE.ArrowHelper(
    new THREE.Vector3(),
    new THREE.Vector3(),
    .25,
    0xffff00);
scene.add(arrowHelper);

const material: THREE.MeshNormalMaterial = new THREE.MeshNormalMaterial()

const boxGeometry: THREE.BoxGeometry = new THREE.BoxGeometry(.2, .2, .2)
const coneGeometry = new THREE.ConeGeometry(.05, .2, 8);

const raycaster = new THREE.Raycaster();
const sceneMeshes = []

const loader = new GLTFLoader()
loader.load(
    'models/monkey_textured.glb',
    function (gltf) {
        gltf.scene.traverse(function (child) {
            if ((<THREE.Mesh>child).isMesh) {
                let m = <THREE.Mesh>child
                m.receiveShadow = true
                m.castShadow = true;
                (<THREE.MeshStandardMaterial>m.material).flatShading = true
                sceneMeshes.push(m)
            }
            if ((<THREE.Light>child).isLight) {
                let l = <THREE.Light>child
                l.castShadow = true
                l.shadow.bias = -.003
                l.shadow.mapSize.width = 2048
                l.shadow.mapSize.height = 2048
            }
        })
        scene.add(gltf.scene);
        //sceneMeshes.push(gltf.scene)
    },
    (xhr) => {
        console.log((xhr.loaded / xhr.total * 100) + '% loaded')
    },
    (error) => {
        console.log(error);
    }
);

window.addEventListener('resize', onWindowResize, false)
function onWindowResize() {
    camera.aspect = window.innerWidth / window.innerHeight
    camera.updateProjectionMatrix()
    renderer.setSize(window.innerWidth, window.innerHeight)
    render()
}

renderer.domElement.addEventListener('dblclick', onDoubleClick, false);
renderer.domElement.addEventListener('mousemove', onMouseMove, false);

function onMouseMove(event) {
    const mouse = {
        x: (event.clientX / renderer.domElement.clientWidth) * 2 - 1,
        y: -(event.clientY / renderer.domElement.clientHeight) * 2 + 1
    }

    //console.log(mouse)

    raycaster.setFromCamera(mouse, camera);

    const intersects = raycaster.intersectObjects(sceneMeshes, false);

    if (intersects.length > 0) {
        //console.log(sceneMeshes.length + " " + intersects.length)
        //console.log(intersects[0])
        //console.log(intersects[0].object.userData.name + " " + intersects[0].distance + " ")
        //console.log(intersects[0].face.normal)
        // line.position.set(0, 0, 0);
        // line.lookAt(intersects[0].face.normal);
        // line.position.copy(intersects[0].point);


        let n = new THREE.Vector3();
        n.copy(intersects[0].face.normal);
        n.transformDirection(intersects[0].object.matrixWorld);

        arrowHelper.setDirection(n);
        arrowHelper.position.copy(intersects[0].point);
    }
}


function onDoubleClick(event) {
    const mouse = {
        x: (event.clientX / renderer.domElement.clientWidth) * 2 - 1,
        y: -(event.clientY / renderer.domElement.clientHeight) * 2 + 1
    }
    raycaster.setFromCamera(mouse, camera);

    const intersects = raycaster.intersectObjects(sceneMeshes, false);

    if (intersects.length > 0) {

        let n = new THREE.Vector3();
        n.copy(intersects[0].face.normal);
        n.transformDirection(intersects[0].object.matrixWorld);

        //const cube: THREE.Mesh = new THREE.Mesh(boxGeometry, material)
        const cube: THREE.Mesh = new THREE.Mesh(coneGeometry, material)

        cube.lookAt(n);
        cube.rotateX(Math.PI / 2)
        cube.position.copy(intersects[0].point);
        cube.position.addScaledVector(n, .1)

        scene.add(cube)
        sceneMeshes.push(cube)
    }
}

const stats = Stats()
document.body.appendChild(stats.dom)

var animate = function () {
    requestAnimationFrame(animate)

    controls.update()

    // if (sceneMeshes.length > 1) {
    //     sceneMeshes[1].rotation.x += .002
    // }

    render()

    stats.update()
};

function render() {
    renderer.render(scene, camera)
}
animate();

Raycaster