code: function RenderTexture(width, height)
  {
      EventTarget.call( this );
  
      this.width = width || 100;
      this.height = height || 100;
  
      this.identityMatrix = mat3.create();
  
      this.frame = new Rectangle(0, 0, this.width, this.height);
  
      if(globals.gl)
      {
          this.initWebGL();
      }
      else
      {
          this.initCanvas();
      }
  }
docs: A RenderTexture is a special texture that allows any pixi displayObject to be rendered to it.
  
  __Hint__: All DisplayObjects (exmpl. Sprites) that renders on RenderTexture should be preloaded.
  Otherwise black rectangles will be drawn instead.
  
  RenderTexture takes snapshot of DisplayObject passed to render method. If DisplayObject is passed to render method, position and rotation of it will be ignored. For example:
  
  var renderTexture = new RenderTexture(800, 600);
  var sprite = Sprite.fromImage("spinObj_01.png");
  sprite.position.x = 800/2;
  sprite.position.y = 600/2;
  sprite.anchor.x = 0.5;
  sprite.anchor.y = 0.5;
  renderTexture.render(sprite);
  
  Sprite in this case will be rendered to 0,0 position. To render this sprite at center DisplayObjectContainer should be used:
  
  var doc = new DisplayObjectContainer();
  doc.addChild(sprite);
  renderTexture.render(doc);  // Renders to center of renderTexture
  
  @class RenderTexture
  @extends Texture
  @constructor
  @param width {Number} The width of the render texture
  @param height {Number} The height of the render texture