Question

87

Jquery/Javascript Opacity animation with scroll

rated 0 times [ 94] [ 7] / answers: 1 / hits: 51663 / 13 Years ago, mon, january 2, 2012, 12:00:00

I'm looking to change the opacity on an object (and have the transition be animated) based on a users scroll.
example(http://davegamache.com/)

I've searched everywhere
like here, but it ends up pointing me to the waypoints plugin (http://stackoverflow.com/questions/6316757/opacity-based-on-scroll-position)

I've implemented the [waypoints][1] plugin and have the object fading once it's higher than 100px. [Using the offet attribute] but would like to basically control the opacity of an object and have the animation be visible like the above example.

I've searched all over- this is my last resort.
Any help is greatly appreciated.

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gleng

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3 Years ago

answered 13 Years ago ryanulyssesb · Accepted Answer

working exemple with starting and ending point here:
http://jsfiddle.net/z7E9u/1/

I copy paste basic code here

    var fadeStart=100 // 100px scroll or less will equiv to 1 opacity

    ,fadeUntil=200 // 200px scroll or more will equiv to 0 opacity

    ,fading = $('#fading')

;



$(window).bind('scroll', function(){

    var offset = $(document).scrollTop()

        ,opacity=0

    ;

    if( offset<=fadeStart ){

        opacity=1;

    }else if( offset<=fadeUntil ){

        opacity=1-offset/fadeUntil;

    }

    fading.css('opacity',opacity).html(opacity);

});