BabylonJS Solar System or at least a sun with some planets

Recently I've started to experiment a bit with BabylonJS. Its nice WebGL framework for web. As an exercise I made this small example - moving and rotating solar system.

You can check the working example here - WebGL Solar System



Here is the full source code of the example: solar.js

var canvas;
var engine;
var scene;

var sun;
var planet1;
var planet2;
var planet2Moon;

function start() {
    canvas = document.getElementById("renderCanvas");
        
    engine = new BABYLON.Engine(canvas, true);    
    
    scene = createScene();
    
    engine.runRenderLoop(function () {
        scene.render();
    });
    
    var c = 0;
    var i = 0;
    scene.beforeRender = function () {
  planet1.position = new BABYLON.Vector3(20 * Math.sin(c), 0, 20 * Math.cos(c));
                
                planet2.position = new BABYLON.Vector3(30 * Math.sin(i), 3 * Math.cos(i), 30 * Math.cos(i));
  moon.position = new BABYLON.Vector3(5 * Math.sin(c), moon.parent.position.y, 5 * Math.cos(c));
    
  c += 0.005;
                i += 0.008;     
    };
    
    window.addEventListener("resize", function () {
        engine.resize();
    });
}

var createScene = function () {

    var scene = new BABYLON.Scene(engine);

    scene.clearColor = new BABYLON.Color3(0, 0.1, 0.1);

   var camera = new BABYLON.ArcRotateCamera("ArcRotateCamera", 1, 0.8, 50, new BABYLON.Vector3(0, 0, 0), scene);
   camera.attachControl(canvas, false);
    
    var light = new BABYLON.HemisphericLight("light1", new BABYLON.Vector3(0, 1, 0), scene);    
    light.intensity = 0.5;
    light.diffuse = new BABYLON.Color3(1, 1, 1);
    
    var light0 = new BABYLON.PointLight("Omni0", new BABYLON.Vector3(1, 10, 1), scene);
    light0.diffuse = new BABYLON.Color3(1, 0.5, 0);
    light0.specular = new BABYLON.Color3(1, 1, 1);
        
    sun = BABYLON.Mesh.CreateSphere("sun", 20.0, 20.0, scene, false,  BABYLON.Mesh.DEFAULTSIDE);
    
    var sunmaterial = new BABYLON.StandardMaterial('sunmaterial', scene);    
    sunmaterial.diffuseColor = new BABYLON.Color3(1.00, 1.00, 1.00);
    sunmaterial.emissiveColor = new BABYLON.Color3(1.00, 0.72, 0.00);
    sunmaterial.ambientColor = new BABYLON.Color3(0.94, 0.85, 0.36);
    sunmaterial.specularColor = new BABYLON.Color3(1.00, 1.00, 1.00);
    sun.material = sunmaterial;
    
    planet1 = BABYLON.Mesh.CreateSphere("planet1", 10.0, 3.0, scene, false,  BABYLON.Mesh.DEFAULTSIDE);            
    var planet1mat = new BABYLON.StandardMaterial('planet1mat', scene);    
    var planet1mat_diffuseTexture = new BABYLON.Texture('assets/planet1.png', scene); 
    planet1mat.diffuseTexture = planet1mat_diffuseTexture;
    planet1mat.specularColor = new BABYLON.Color3(0, 0, 0);
    planet1.material = planet1mat;
    
    var frameRate = 10;
    var yRotate = new BABYLON.Animation("yRotate", "rotation.y", frameRate, BABYLON.Animation.ANIMATIONTYPE_FLOAT, BABYLON.Animation.ANIMATIONLOOPMODE_CYCLE);
    var keyFramesR = []; 
    keyFramesR.push({
        frame: 0,
        value: 0
    });
    keyFramesR.push({
        frame: frameRate,
        value: Math.PI
    });
    keyFramesR.push({
        frame: 2 * frameRate,
        value: 2 * Math.PI
    });
    yRotate.setKeys(keyFramesR);
    scene.beginDirectAnimation(planet1, [yRotate], 0, 2 * frameRate, true);   
    
    planet2 = BABYLON.Mesh.CreateSphere("planet2", 10.0, 5.0, scene, false,  BABYLON.Mesh.DEFAULTSIDE);        
    moon = BABYLON.Mesh.CreateSphere("moon", 3.0, 1.0, scene, false,  BABYLON.Mesh.DEFAULTSIDE);
    moon.translate(planet2.position, 5, BABYLON.Space.WORLD);
    moon.parent = planet2;
    
    var planet2mat = new BABYLON.StandardMaterial('planet2mat', scene);    
    var planet2mat_diffuseTexture = new BABYLON.Texture('assets/planet2.jpg', scene); 
    planet2mat.diffuseTexture = planet2mat_diffuseTexture;    
    planet2mat.specularColor = new BABYLON.Color3(0, 0, 0);
    
    planet2.material = planet2mat;
    
    var yRotate = new BABYLON.Animation("yRotate", "rotation.y", frameRate/2, BABYLON.Animation.ANIMATIONTYPE_FLOAT, BABYLON.Animation.ANIMATIONLOOPMODE_CYCLE);
    yRotate.setKeys(keyFramesR);
    scene.beginDirectAnimation(planet2, [yRotate], 0, 2 * frameRate, true);   
    
    return scene;

  };