BabylonJS - 线段

线段是 3D 游戏中的基本元素。要绘制线段，需要两点才能在它们之间绘制线段。

演示

<!doctype html>
<html>
   <head>
      <meta charset = "utf-8">
      <title>BabylonJs - Basic Element-Creating Scene</title>
      <script src = "babylon.js"></script>
      <style>
         canvas {width: 100%; height: 100%;}
      </style>
   </head>

   <body>
      <canvas id = "renderCanvas"></canvas>
      <script type = "text/javascript">
         var canvas = document.getElementById("renderCanvas");
         var engine = new BABYLON.Engine(canvas, true);
         var createScene  = function() {
            var scene = new BABYLON.Scene(engine);
            scene.clearColor = new BABYLON.Color3( .5, .5, .5);
            
            var camera = new BABYLON.ArcRotateCamera("camera1",  0, 0, 0, new BABYLON.Vector3(0, 0, -0), scene);
            camera.setPosition(new BABYLON.Vector3(0, 0, -100));
            camera.attachControl(canvas, true);
            
            var light = new BABYLON.HemisphericLight("light1", new BABYLON.Vector3(1, 0.5, 0), scene);
            light.intensity = 0.7;
            
            var pl = new BABYLON.PointLight("pl", new BABYLON.Vector3(0, 0, 0), scene);
            pl.diffuse = new BABYLON.Color3(1, 1, 1);
            pl.specular = new BABYLON.Color3(1, 0, 0);
            pl.intensity = 0.95;


            // lines creation
            var path = [];
            for(var t = 0; t < 40; t++) {
               var x = t*Math.cos(5*t);
               var y = t*Math.sin(5*t);
               var z = 0;
               path.push(new BABYLON.Vector3(x, y, z));
            }
            
            var mesh = BABYLON.Mesh.CreateLines("lines", path, scene, true);

            var k = 0;
            scene.registerBeforeRender(function() {			
               pl.position = camera.position;
            });
            return scene; 
         };
         var scene = createScene();
         engine.runRenderLoop(function() {
            scene.render();
         });
      </script>
   </body>
</html>

输出

以上代码行生成以下输出 −

要获取沿 x 和 y 轴的坐标，请使用以下方程式（数学函数）并使用 x 和 y 值创建路径。与 babylonjs 的 createline 类相同。使用您选择的任意方程式，尝试创建不同的线段。

var mesh = BABYLON.Mesh.CreateLines("lines", path, scene, true);

使用以下方程式创建线段 −

var x = t*Math.cos(5*t);
var y = t*Math.sin(5*t);
var z = 0;

t 的值从 0 到 40。

执行以下代码行时，形状会发生变化 −

var x = t * Math.cos(6 * t);
var y = t * Math.sin(6 * t);
var z = 0;

线段的形状如下所示 −

babylonjs_parametric_shapes.htm

打印页面