三.js鼠标滚轮可向上/向下移动相机，而不是放大/缩小

Question

你是怎么做到的？我使用 Three.js 编辑器创建了一个场景，并使用"发布"选项下载了项目。我编辑了应用程序.js文件以导入OrbitControls，因此现在我可以使用鼠标滚轮(或在我的情况下为Apple Magic Mouse 2触控板表面(来放大/缩小场景。但是，我不希望鼠标滚轮缩放，我希望它"滚动"(沿 Y 轴向上/向下移动相机，而不是 Z 轴(。有没有办法做到这一点？OrbitControls是实现这一目标的方式，还是只会增加复杂性？这是我的应用程序.js：

import {OrbitControls} from './OrbitControls.js'; // Added
var APP = {
Player: function ( THREE ) {
window.THREE = THREE; // FIX for editor scripts (they require THREE in global namespace)
var loader = new THREE.ObjectLoader();
var camera, scene, renderer;
var events = {};
var dom = document.createElement( 'div' );
dom.className = "threejs-app";
this.dom = dom;
this.width = 500;
this.height = 500;
this.load = function ( json ) {
renderer = new THREE.WebGLRenderer( { antialias: true } );
renderer.outputEncoding = THREE.sRGBEncoding;
renderer.setClearColor( 0x000000 );
renderer.setPixelRatio( window.devicePixelRatio );
var project = json.project;
if ( project.shadows ) renderer.shadowMap.enabled = true;
if ( project.vr ) renderer.xr.enabled = true;
dom.appendChild( renderer.domElement );
this.setScene( loader.parse( json.scene ) );
this.setCamera( loader.parse( json.camera ) );
var controls = new OrbitControls( camera, renderer.domElement ); // Added
events = {
init: [],
start: [],
stop: [],
keydown: [],
keyup: [],
mousedown: [],
mouseup: [],
mousemove: [],
touchstart: [],
touchend: [],
touchmove: [],
update: []
};
var scriptWrapParams = 'player,renderer,scene,camera';
var scriptWrapResultObj = {};
for ( var eventKey in events ) {
scriptWrapParams += ',' + eventKey;
scriptWrapResultObj[ eventKey ] = eventKey;
}
var scriptWrapResult = JSON.stringify( scriptWrapResultObj ).replace( /"/g, '' );
for ( var uuid in json.scripts ) {
var object = scene.getObjectByProperty( 'uuid', uuid, true );
if ( object === undefined ) {
console.warn( 'APP.Player: Script without object.', uuid );
continue;
}
var scripts = json.scripts[ uuid ];
for ( var i = 0; i < scripts.length; i ++ ) {
var script = scripts[ i ];
var functions = ( new Function( scriptWrapParams, script.source + 'nreturn ' + scriptWrapResult + ';' ).bind( object ) )( this, renderer, scene, camera );
for ( var name in functions ) {
if ( functions[ name ] === undefined ) continue;
if ( events[ name ] === undefined ) {
console.warn( 'APP.Player: Event type not supported (', name, ')' );
continue;
}
events[ name ].push( functions[ name ].bind( object ) );
}
}
}
dispatch( events.init, arguments );
};
this.setCamera = function ( value ) {
camera = value;
camera.aspect = this.width / this.height;
camera.updateProjectionMatrix();
};
this.setScene = function ( value ) {
scene = value;
};
this.setSize = function ( width, height ) {
this.width = width;
this.height = height;
if ( camera ) {
camera.aspect = this.width / this.height;
camera.updateProjectionMatrix();
}
if ( renderer ) {
renderer.setSize( width, height );
}
};
function dispatch( array, event ) {
for ( var i = 0, l = array.length; i < l; i ++ ) {
array[ i ]( event );
}
}
var time, prevTime;
function animate() {
time = performance.now();
try {
dispatch( events.update, { time: time, delta: time - prevTime } );
} catch ( e ) {
console.error( ( e.message || e ), ( e.stack || "" ) );
}
renderer.render( scene, camera );
prevTime = time;
}
this.play = function () {
prevTime = performance.now();
document.addEventListener( 'keydown', onDocumentKeyDown );
document.addEventListener( 'keyup', onDocumentKeyUp );
document.addEventListener( 'mousedown', onDocumentMouseDown );
document.addEventListener( 'mouseup', onDocumentMouseUp );
document.addEventListener( 'mousemove', onDocumentMouseMove );
document.addEventListener( 'touchstart', onDocumentTouchStart );
document.addEventListener( 'touchend', onDocumentTouchEnd );
document.addEventListener( 'touchmove', onDocumentTouchMove );
dispatch( events.start, arguments );
renderer.setAnimationLoop( animate );
};
this.stop = function () {
document.removeEventListener( 'keydown', onDocumentKeyDown );
document.removeEventListener( 'keyup', onDocumentKeyUp );
document.removeEventListener( 'mousedown', onDocumentMouseDown );
document.removeEventListener( 'mouseup', onDocumentMouseUp );
document.removeEventListener( 'mousemove', onDocumentMouseMove );
document.removeEventListener( 'touchstart', onDocumentTouchStart );
document.removeEventListener( 'touchend', onDocumentTouchEnd );
document.removeEventListener( 'touchmove', onDocumentTouchMove );
dispatch( events.stop, arguments );
renderer.setAnimationLoop( null );
};
this.dispose = function () {
while ( dom.children.length ) {
dom.removeChild( dom.firstChild );
}
renderer.dispose();
camera = undefined;
scene = undefined;
renderer = undefined;
};
//
function onDocumentKeyDown( event ) {
dispatch( events.keydown, event );
}
function onDocumentKeyUp( event ) {
dispatch( events.keyup, event );
}
function onDocumentMouseDown( event ) {
dispatch( events.mousedown, event );
}
function onDocumentMouseUp( event ) {
dispatch( events.mouseup, event );
}
function onDocumentMouseMove( event ) {
dispatch( events.mousemove, event );
}
function onDocumentTouchStart( event ) {
dispatch( events.touchstart, event );
}
function onDocumentTouchEnd( event ) {
dispatch( events.touchend, event );
}
function onDocumentTouchMove( event ) {
dispatch( events.touchmove, event );
}
}
};
export { APP };

<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/110/three.min.js"></script>

Answer 1

我没有您项目的详细信息，但似乎您需要实现自己的婴儿车模块。

我该怎么做，张？

好吧，我年轻的Padawan，我们只需要实现一个功能，如您所提到的将相机向上/向下移动。

所以，你的意思是OrbitControls只是增加了复杂性？

现在，如果这是您唯一需要的相机移动，那么它确实如此。

让我们实现它。

首先，我们添加window.addEventListener('wheel', onMouseWheel, false);来收听鼠标滚轮。然后我们调用event.preventDefault();方法来防止缩放。

现在，我们计算滚动修饰符camera.position.y += event.deltaY / 1000;。在这种情况下，我们使用 Y 轴上的增量。对于此示例，该值非常高，因此我除以1000以使滚动更流畅。

最后，我们添加camera.position.clampScalar(0, 10);以防止越界滚动。

let camera, scene, renderer;
let geometry, material, mesh;
init();
animate();
function init() {
camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 0.01, 10);
camera.position.z = 1;
scene = new THREE.Scene();
geometry = new THREE.BoxGeometry(0.2, 0.2, 0.2);
material = new THREE.MeshNormalMaterial();
mesh = new THREE.Mesh(geometry, material);
scene.add(mesh);
renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
window.addEventListener('wheel', onMouseWheel, false);
window.addEventListener('resize', onWindowResize, false);
}

function animate() {
requestAnimationFrame(animate);
mesh.rotation.x += 0.01;
mesh.rotation.y += 0.02;
renderer.render(scene, camera);
}

function onMouseWheel(ev) {
event.preventDefault();
camera.position.y += event.deltaY / 1000;
// prevent scrolling beyond a min/max value
camera.position.clampScalar(0, 10);
}

function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/110/three.min.js"></script>

Answer 2

如果垂直滚动是你需要的唯一行为，那么是的，添加OrbitControls会增加不必要的复杂性，因为你可以使用默认的JavaScript API轻松实现它：

// Add listener to respond to the "wheel" event
window.addEventListener("wheel", onMouseWheel);
function onMouseWheel(event){
camera.position.y += event.deltaY * 10;
}

* 10倍数取决于场景的大小，以及您希望摄像机垂直移动的速度。