parallax scrolling issue - div element jerking when scrolling in webkit browsers

Question

I have created a parallax scroll, which seem to be working fine in firefox however in the chrome browser there's a slight jump on the body text when scrolling. click here scroll to the about section. I am not sure if t this is a css or JS issue.. below is a snippet i have incorporated into my parallax function

Does anyone know how i an fix this issue?

$(document).ready(function(){

// Cache the Window object
$window = $(window);

// Cache the Y offset and the speed of each sprite
$('[data-type]').each(function() {  
    $(this).data('offsetY', parseInt($(this).attr('data-offsetY')));
    $(this).data('Xposition', $(this).attr('data-Xposition'));
    $(this).data('speed', $(this).attr('data-speed'));
});

// For each element that has a data-type attribute
$('[data-type="background"]').each(function(){


    // Store some variables based on where we are
    var $self = $(this),
        offsetCoords = $self.offset(),
        topOffset = offsetCoords.top;


    // When the window is scrolled...
    $(window).scroll(function() {

        // If this section is in view
        if ( ($window.scrollTop() + $window.height()) > (topOffset) &&
             ( (topOffset + $self.height()) > $window.scrollTop() ) ) {

            // Scroll the background at var speed
            // the yPos is a negative value because we're scrolling it UP!                              
            var yPos = -($window.scrollTop() / $self.data('speed')); 

            // If this element has a Y offset then add it on
            if ($self.data('offsetY')) {
                yPos += $self.data('offsetY');
            }

            // Put together our final background position
            var coords = '50% '+ yPos + 'px';

            // Move the background
            $self.css({ backgroundPosition: coords });

           $('[data-type="scroll-text"]', $self).each(function() {
                    var $text= $(this);
                     var pos = ($window.scrollTop()/10) * $text.data('speed');
                     var curP = $text.css('margin-top'); 
                     var is_chrome = navigator.userAgent.toLowerCase().indexOf('chrome') > -1;
                     if(is_chrome) {
                         $text.animate({
                         paddingTop: pos,
                        }, 200, 'linear', function() {
                            // Animation complete.
                        });
                     } else {
                     $text.css('padding-top', pos);
                     }
            }); 

        }; // in view

    }); // window scroll

}); // each data-type


      }); // document ready

Rhyme

Your code would benefit from simple optimizations: 1) Call $(window).scrollTop() just once and cache the value, 2) Query the DOM for the [data-text] elements outside of the event listener. – Harijan

@IanKuca can you elaborate on this abit, or even edit the JS on github. I'm not the greatest at Javascript – Rhyme

pastebin.com/JCaA7T6A – Harijan

@IanKuca with that script i get the following error message..."Uncaught ReferenceError: $self is not defined" – Rhyme

You need to have the $self variable defined before the part of the code I edited. Think a little. – Harijan

@IanKuca Yup done that still hasn't solved the issue – Rhyme

Fun thing: on a non-maximized Firefox window, I can get this to scroll forever. – Temperance

@Temperance i don't quite understand what you mean – Rhyme

Answer 1

Some suggestions:

1.) Use position: fixed to avoid any jitter, as you'll be taking the element out of the document flow. You can then position it using z-index.

2.) Cache as much as you can to ease processing time.

3.) Math.round may not be necessary, but try adding this CSS to your moving areas: -webkit-transform: translate3d(0,0,0); This will force hardware acceleration in Chrome, which may ease some of the jittering. (It looked smoother on my screen when I added this with Inspector, but it didn't get rid of the jumpiness with the scroll wheel.) Note: Don't do this on your entire document (e.g. body tag), as it might cause some issues with your current layout. (Your navigation bar didn't stick to the top of the window, for instance.)

4.) If you have any animations running as part of your parallax logic (tweening the margin into place or something along those lines), remove it - that would probably cause the jump you see.

Hope this helps. Best of luck.

Beguine

Not sure if it's important, but, since the question is asking for "webkit" browsers - iOS Safari and Android Chrome both have trouble handling position: fixed. Not sure if mobile is important, but they are webkit browsers. iOS 5 and 6 are a little better, but iOS 4 and most recent Android treat position fixed very poorly – Catherine

I had a jitter issue and position:fixed worked for me. Thanks! – Estate

I had a related problem with parallax scroll that only occurred in Chrome (Win7). My elements were being repositioned 'onscroll' and everything was adjusting correctly, but when I used the mouse wheel to scroll -and only with the mouse wheel- the whole top/bottom edge of the viewport would jump about 100px or so and reveal what looked like a transparent area inside the browser window with no content (you know, that gray/white checkered pattern). This little glitch would repeat rapidly... Your suggestion to add -webkit-transform: translate3d(0,0,0); to the moving elements solved my issue. – Howling

Answer 2

I see the same jittering in FireFox and Chrome (Mac). Looking at your containers, one thing that's glaring at me is the pixel position that's being calculated/used.

Chrome: <div id="about-title" style="margin-top: 1562.3999999999999px;">
FireFox: <div id="about-title" style="margin-top: 1562.4px;">

Browsers aren't going to allow content to sit at 1/2 pixel, let alone 0.3999999 of a pixel. I think it's moving it, and trying to calculate whether to round up or round down. It jitters because it's calculating with every click of your mouse wheel.

Thus, I'd try adding Math.round() to your positions so that the containers are never being left in limbo.

Take a look at the code here: http://webdesigntutsplus.s3.amazonaws.com/tuts/338_parallax/src/index.html

Firebug some of the elements, and you'll see that their only fraction of a pixel is '0.5'. Most of them (the bulk) go to round number values.

Bassoon

I was having an issue if you scrolled really fast up and "jammed" into the top that some elements would get out of sync and potentially be hundreds of pixels off. This fixed that issue flawlessly! Thank You! – Eon

Answer 3

You are going to have to change the way that the scrolling works (i.e. change how the spacing is computed), but this can be fixed by adding the position:fixed CSS element to the page elements that are scrolling. The problem is coming from the time that it takes for the JavaScript to process and then render.

For example, on your page you would set each of the <div> tags containing text to have a fixed position and then use the JavaScript/JQuery function to update the top: CSS element. This should make the page scroll smoothly.

Psalms

Answer 4

Have you tried adding the preventdefault inside the scroll function?

$(window).scroll(function(e) {
    e.preventDefault();
    // rest of your code
}

Foulard

Answer 5

In a previous question I created a fairly good parallax scrolling implementation. Jquery Parallax Scrolling effect - Multi directional You might find it useful.

Here's the JSFiddle http://jsfiddle.net/9R4hZ/40/ use the up/down arrows or scroll wheel.

Using padding and margin for the positioning are probably why you're experiencing rendering issues. While my code uses scroll or keyboard input for the effect you can loop the relavent portion and check the $moving variable until you reach the desired element on screen.

function parallaxScroll(scroll) {
    // current moving object
    var ml = $moving.position().left;
    var mt = $moving.position().top;
    var mw = $moving.width();
    var mh = $moving.height();
    // calc velocity
    var fromTop = false;
    var fromBottom = false;
    var fromLeft = false;
    var fromRight = false;
    var vLeft = 0;
    var vTop = 0;
    if($moving.hasClass('from-top')) {
        vTop = scroll;
        fromTop = true;
    } else if($moving.hasClass('from-bottom')) {
        vTop = -scroll;
        fromBottom = true;
    } else if($moving.hasClass('from-left')) {
        vLeft = scroll;
        fromLeft = true;
    } else if($moving.hasClass('from-right')) {
        vLeft = -scroll;
        fromRight = true;
    }
    // calc new position
    var newLeft = ml + vLeft;
    var newTop = mt + vTop;
    // check bounds
    var finished = false;
    if(fromTop && (newTop > t || newTop + mh < t)) {
        finished = true;
        newTop = (scroll > 0 ? t : t - mh);
    } else if(fromBottom && (newTop < t || newTop > h)) {
        finished = true;
        newTop = (scroll > 0 ? t : t + h);
    } else if(fromLeft && (newLeft > l || newLeft + mw < l)) {
        finished = true;
        newLeft = (scroll > 0 ? l : l - mw);
    } else if(fromRight && (newLeft < l || newLeft > w)) {
        finished = true;
        newLeft = (scroll > 0 ? l : l + w);
    }
    // set new position
    $moving.css('left', newLeft);
    $moving.css('top', newTop);
    // if finished change moving object
    if(finished) {
        // get the next moving
        if(scroll > 0) {
            $moving = $moving.next('.parallax');
            if($moving.length == 0)
                $moving = $view.find('.parallax:last');
        } else {
            $moving = $moving.prev('.parallax');
            if($moving.length == 0)
                $moving = $view.find('.parallax:first');
        }
    }
    // for debug
    $('#direction').text(scroll + " " + l + "/" + t + " " + ml + "/" + mt + " " + finished + " " + $moving.text());
}

Malignity

Answer 6

May not be related to your specifics, but I had a jumpy parallax scrolling problem, I was able to solve it adding the following CSS for the fixed portions of the page:

@supports (background-attachment: fixed)
{
    .fixed-background
    {
        background-attachment: fixed;
    }
}

Not sure of all the specifics, but found at Alternate Fixed & Scroll Backgrounds

Triclinic

Answer 7

here .unbind("scroll") worked for me

$(window).unbind("scroll").on("scroll", function(){

Lately