Revolving Planet
Here’s my second attempt at getting a planet to revolve… this time I used trig to push it around in a circle, instead of just rotating its container as I did before. Here is the result:
Note: It uses the Sphere class for the ‘planet’.
If you don’t see a revolving sphere above, then you need to install the flash player 10, which you can get here:
http://labs.adobe.com/downloads/flashplayer10.html
The Code
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import flash.display.Sprite;
import flash.events.Event;
public class Threed2 extends Sprite {
private var centerX:Number = 200;
private var centerY:Number = 200;
private var centerZ:Number = 0;
private var sphere:Sphere;
private var radius:Number = 200;
private var angle:Number = 0;
private var speed:Number = 0.05;
private var planets:Array;
public function Threed2() {
init();
}
private function init():void {
planets = [];
//angle is rotation angle around centre
angle = 0;
//add a planet
addPlanet(0x00ff00,100,200);
addEventListener(Event.ENTER_FRAME, function(e:Event):void {
revolvePlanets();
});
}
private function revolvePlanets():void {
for(var i:int = 0; i < planets.length; i++){
var planet:Sphere = planets[i];
angle+=speed;
planet.x = centerX + Math.cos(angle)*radius;
planet.z = centerZ + Math.sin(angle)*radius;
}
}
private function addPlanet(pcolor:uint=0xff0000, psize:Number=30,orbit:Number=150):void {
//create 'planet'
var planet:Sphere = new Sphere(psize, pcolor);
planet.x = orbit;
planet.y = orbit;
addChild(planet);
planets.push(planet);
}
}
}
// Copyright (c) 2008 David Wilhelm
// MIT license: http://www.opensource.org/licenses/mit-license.php