three.js 显示一条线

时间 2021-07-10
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>Three框架</title>
        <script src="libs/Three.js" data-ke-src="js/Three.js"></script>
        <style type="text/css">
            div#canvas-frame {
                border: none;
                cursor: pointer;
                width: 100%;
                height: 600px;
                background-color: #EEEEEE;
            }

        </style>
        <script>
            var renderer;
            function initThree() {
                width = document.getElementById('canvas-frame').clientWidth;
                height = document.getElementById('canvas-frame').clientHeight;
                renderer = new THREE.WebGLRenderer({
                    antialias : true
                });
                renderer.setSize(width, height);
                document.getElementById('canvas-frame').appendChild(renderer.domElement);
                renderer.setClearColor(0xFFFFFF, 1.0);
            }

            var camera;
            function initCamera() {
                camera = new THREE.PerspectiveCamera(45, width / height, 1, 10000);
                camera.position.x = 0;
                camera.position.y = 1000;
                camera.position.z = 0;
                camera.up.x = 0;
                camera.up.y = 0;
                camera.up.z = 1;
                camera.lookAt({
                    x : 0,
                    y : 0,
                    z : 0
                });
            }

            var scene;
            function initScene() {
                scene = new THREE.Scene();
            }

            var light;
            function initLight() {
                light = new THREE.DirectionalLight(0xFF0000, 1.0, 0);
                light.position.set(100, 100, 200);
                scene.add(light);
            }

            var cube;
            function initObject() {

                var geometry = new THREE.Geometry();//声明一个几何体
                var material = new THREE.LineBasicMaterial( { vertexColors: THREE.VertexColors} );
            //定义一种线条的材质，使用THREE.LineBasicMaterial类型来定义
            //使用了顶点颜色vertexColors: THREE.VertexColors，就是线条的颜色会根据顶点来计算
                var color1 = new THREE.Color( 0x444444 ), color2 = new THREE.Color( 0xFF0000 );
            //线的材质可以由2点的颜色决定  定义两种颜色，分别表示线条两个端点的颜色
            
                var p1 = new THREE.Vector3( -100, 0, 100 );//定义2个顶点的位置，并放到geometry中
                var p2 = new THREE.Vector3(  100, 0, -100 );
                geometry.vertices.push(p1);
                geometry.vertices.push(p2);
                geometry.colors.push( color1, color2 );//为2个顶点设置不同的颜色

                var line = new THREE.Line( geometry, material, THREE.LinePieces );//定义线条，使用THREE.Line类,几何体，线条材质，点的连接方式
                scene.add(line);//将这条线加入到场景中
            }
            function render()
            {
                renderer.clear();
                renderer.render(scene, camera);
                requestAnimationFrame(render);
            }
            function threeStart() {
                initThree();
                initCamera();
                initScene();
                initLight();
                initObject();
                render();
            }

        </script>
    </head>

    <body onload="threeStart();">
        <div id="canvas-frame"></div>
    </body>
</html>