possible to track the tap position on display screen ?

Hi eL Be,

Do you want to convert the touch position to world space? If so you can use the screenSpaceToWorldSpace() function found on the Camera component. You can check the details here: https://lensstudio.snapchat.com/api/classes/Camera/

Here's a quick example of finding world space position from touch:

//@input Component.Camera camera

script.createEvent("TouchStartEvent").bind(function(data){
    var touchPos = data.getTouchPosition();
    var depth = 1.0;
    var worldPos = script.camera.screenSpaceToWorldSpace(touchPos, depth);
    print(worldPos.x + ", " + worldPos.y + ", " + worldPos.z);
});

If you want to convert the touch position to the units used by SpriteAligner, you can translate like this:

var alignerPos = new vec2(
    (touchPos.x - 0.5) * 2.0,
    (touchPos.y - 0.5) * -2.0
);

And here's a full example script using that:

//@input Component.SpriteAligner aligner

script.createEvent("TouchStartEvent").bind(function(data){
    var touchPos = data.getTouchPosition();
    var alignerPos = new vec2(
        (touchPos.x - 0.5) * 2.0,
        (touchPos.y - 0.5) * -2.0
    );
    script.aligner.bindingPoint = alignerPos;
});

Hope this answers your question!