best way to move a sprite

[timmyelliot]

Hi,

 

I was trying to move a sprite using keyboard 'a' and 'd,' using the sprite sample from the playgroud saved here:

 

 http://www.babylonjs-playground.com/#14OAYQ#12

(lines 37 - 46, also listed below)

 

The movement looks very choppy and flickers, is there a better way of doing this so that the sprite appears to move more smoothly?

 

scene.actionManager = new BABYLON.ActionManager(scene);

 

scene.actionManager.registerAction(

new BABYLON.ExecuteCodeAction(BABYLON.ActionManager.OnKeyDownTrigger, function (evt) {

    if (evt.sourceEvent.keyCode == 65) {

        player.position.x = player.position.x + .05;

        player.invertU = false;

    }

    if(evt.sourceEvent.keyCode == 68){

      player.position.x = player.position.x + -.05; 

      player.invertU = true;

   }

}));

 

[Temechon]

Hello, 

 

You can use registerBeforeRender (that will be called 60 times per seconds). I used window events keydown and keyup to trigger the movement (cause it's a copy paste from a project of mine), but it should work too with ActionManager and OnKeyDownTrigger.

 

http://www.babylonjs-playground.com/#14OAYQ#13

 

Good luck

[fenomas]

It's choppy because it's running off the browser's keyDown events. When you hold down a key, the OS normally fires one key event, then pauses, then fires more at regular intervals, depending on OS settings. It works exactly the same as when you're typing in a text field.

 

To get regular movement you need to use both keyDown and keyUp listeners to track whether keys are down (there is no "isKeyPressed" in JS).

[fenomas]

Incidentally, a while back I wrote a library to manage things like this.

https://github.com/andyhall/game-inputs

 

With that, you'd do something like:

var inputs = require('game-inputs')()inputs.bind( 'moveLeft',  'A', '<left>' )inputs.bind( 'moveRight', 'D', '<right>' )scene.registerBeforeRender(function() {  if (inputs.state.moveLeft) { /* ... */ }  if (inputs.state.moveRight) { /* ... */ }})

[Vousk-prod.]

Nice lib fenomas!