以下是一个web端cad测量面积的示例代码,基于Three.js和jQuery库实现: HTML部分: - <!DOCTYPE html>
- <html>
- <head>
- <meta charset="UTF-8">
- <title>Web端CAD测量面积</title>
- <style>
- canvas {
- width: 100%;
- height: 100%;
- display: block;
- }
- </style>
- </head>
- <body>
- <div id="container"></div>
- <div id="output">
- <p>请点击屏幕选择点开始绘制,再次点击结束绘制并显示面积。</p >
- </div>
- <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
- <script src="https://cdn.bootcdn.net/ajax/libs/three.js/r125/three.min.js"></script>
- <script src="app.js"></script>
- </body>
- </html>
- JavaScript部分(app.js):
- // 初始化Three.js场景、相机、渲染器
- var scene = new THREE.Scene();
- var camera = new THREE.PerspectiveCamera(
- 75, window.innerWidth/window.innerHeight, 0.1, 1000 );
- var renderer = new THREE.WebGLRenderer({ antialias: true });
- renderer.setSize( window.innerWidth, window.innerHeight );
- document.getElementById("container").appendChild(renderer.domElement);
- // 初始化画线的材质
- var material = new THREE.LineBasicMaterial( { color: 0x0000ff } );
- // 初始化测量变量
- var linePoints = [];
- var area = 0;
- // 监听鼠标点击事件,绘制线段并计算面积
- document.addEventListener( 'click', onClick, false );
- function onClick( event ) {
- // 获取鼠标点击坐标
- var mouse = new THREE.Vector2();
- mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
- mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;
- // 创建射线
- var raycaster = new THREE.Raycaster();
- raycaster.setFromCamera( mouse, camera );
- // 计算射线和平面的交点,并绘制线段
- var plane = new THREE.Plane(new THREE.Vector3(0, 0, 1), 0);
- var intersection = new THREE.Vector3();
- raycaster.ray.intersectPlane(plane, intersection);
- linePoints.push(intersection);
- if (linePoints.length > 1) {
- var geometry = new THREE.BufferGeometry().setFromPoints(linePoints);
- var line = new THREE.Line(geometry, material);
- scene.add(line);
- // 计算面积
- var v1 = linePoints[linePoints.length-2];
- var v2 = linePoints[linePoints.length-1];
- area += (v1.x * v2.y - v2.x * v1.y) / 2;
- $("#output").html("<p>面积: " + Math.abs(area).toFixed(2) + "</p >");
- }
- }
- // 渲染场景
- function animate() {
- requestAnimationFrame( animate );
- renderer.render( scene, camera );
- }
- animate();<span style="font-family: 宋体; font-size: 10.5pt; background-color: rgb(255, 255, 255);"> </span>
复制代码这个示例代码可以在浏览器中运行,并实现了在Three.js场景中绘制线段、计算面积等功能,在线CAD有很多其他功能,可以到梦想CAD控件官网查看。以上代码可以根据实际需求对代码进行修改和拓展。
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