Animate drawing a stroke along a bezier path

[greg500]

Hey,
I have some problems with drawing the animation using pixi-tween. I want to animate a drawing of a stroke along the bezier path. I am basis on this example -> https://github.com/Nazariglez/pixi-tween/blob/master/examples/easing.html
 but my code still doesn’t work. Any idea where am I wrong?

That's the code:

var app = new PIXI.Application(1200, 800, {antialias: true});
document.body.appendChild(app.view);

var raf;
    function animate(){
      raf = window.requestAnimationFrame(animate);
      app.render(app.stage);
      PIXI.tweenManager.update();
    }
    function stop(){
      window.cancelAnimationFrame(raf);
    }
  
var path = new PIXI.tween.TweenPath();
  path.moveTo(0.4,0.4);
  path.bezierCurveTo(0.4,360.5,292.29,652.4,652.4,652.4);
  path.bezierCurveTo(87.5,65.4,105.9,47,105.9,24.89);
  path.closed = true;
  
var t = new PIXI.Graphics();
app.stage.addChild(t);

var tween = PIXI.tweenManager.createTween(t);
tween.on('update', function(delta){
 tween.path = path;
 tween.time = 13000;
 tween.easing = PIXI.tween.Easing.outBounce();
 tween.loop = true;
 tween.lineStyle(10, 0xff0000);
 tween.drawPath(path);
 tween.start();
});
animate();

 

[bubamara]

you see no animation, right?

you have to call animate(); first or use app's ticker instead

 

[greg500]

Yes, I called animate() and made some modifications but the stroke isn't animate along the Bezier curve. This is a code:

var app = new PIXI.Application(1200, 800, {antialias: true});
document.body.appendChild(app.view);

var path = new PIXI.tween.TweenPath();
	path.moveTo(0.4, 0.4);
	path.bezierCurveTo(0.4, 360,292, 652, 652, 652);
	path.bezierCurveTo(87, 65, 105, 47, 105, 24);
	path.closed = true;

var t = new PIXI.Graphics();
app.stage.addChild(t);

// t.lineStyle(10, 0xff0000);
// t.drawPath(path);

var tween = PIXI.tweenManager.createTween(t);
   tween.path = path;
   tween.time = 13000;
   tween.easing = PIXI.tween.Easing.outBounce();
   tween.loop = true;
   tween.on('start', function() {
	t.lineStyle(10, 0xff0000);
	t.drawPath(path); });
   tween.start();


app.ticker.add(function(delta){
	PIXI.tweenManager.update();
});

Do you have any idea what should be correct?

[greg500]

I've back to this project again. Any idea where am I wrong?

[ivan.popelyshev]

code looks good. Make a fiddle, people here are very lazy, nobody wants to create html file, download pixi and tweens e.t.c. 

[greg500]

The stroke does not draw but the whole object is move according to the path (unexpected).  

https://jsfiddle.net/kuguar/f5qvkfq0/5/

[ivan.popelyshev]

You have to clear the whole graphics and refill it every frame, or add more lines to the end of it. Anyway, whatever you pass to PIXI.Graphics cant be edited later, only removed completely, if you want to know why, please look in the source code or try to replicate same thing with pure webgl.

[greg500]

Thank you. I understand the idea of how to animate the stroke in pure pixi.js but I wonder if there is an easy way to do this using pixi-tween. I want to use pixi-tween because it's easier to control visual aspects of my project and put quickly some design corrections (for example the speed of drawing the stroke)

[ivan.popelyshev]

According to docs and sources, pixi-tween does not have this feature. Even more, I dont know any plugins that animate Graphics properly except https://github.com/jiborobot/pixi-animate , Adobe Animate exporter.

It would be good to make one.