Rendering transparent lines in WebGL Render creates modern art

https://github.com/pixijs/pixi.js/issues/2046

HTML

<script src="https://cdn.rawgit.com/pixijs/pixi.js/master/bin/pixi.min.js"></script>
<body></body>

JavaScript

var renderer = new PIXI.CanvasRenderer(800, 600);
renderer.clearBeforeRender = false;
document.body.appendChild(renderer.view);

// create the root of the scene graph
var stage = new PIXI.Container();

// create a texture from an image path
var texture = PIXI.Texture.fromImage('http://pixijs.github.io/examples/_assets/basics/bunny.png');

// create a new Sprite using the texture
var bunny = new PIXI.Sprite(texture);

// center the sprite's anchor point
bunny.anchor.x = 0.5;
bunny.anchor.y = 0.5;

// move the sprite to the center of the screen
bunny.position.x = 0;
bunny.position.y = 150;

stage.addChild(bunny);

// start animating
animate();
function animate() {
    requestAnimationFrame(animate);

    // just for fun, let's rotate mr rabbit a little
    bunny.x += 8;

    // render the container
    renderer.render(stage);
}