Alternative to velocity.js
CSS3 - Using -webkit-/-moz-/-o-
This method is compatible with Chrome only. To make it work across different browsers, you can refer to resources like http://www.w3schools.com/css/css3_transitions.asp or explore similar examples like this one which achieves the desired effect on Chrome onhover: http://css-tricks.com/webkit-image-wipes/
As far as I know, the mask attribute functions in Safari, Chrome, and possibly Opera as well.
jQuery
You may find what you're looking for here: http://jquery.malsup.com/cycle/wipe.html
You could also explore this option: Nivo slider effectslicedownright
Other potentially useful resources:
Jquery image transition left to right and fade in, in a slideshow
CSS fade left to right
Fade effect left to right on an image
CSS Fade Between Background Images on Hover
In my view, if one method works effectively, stick with that rather than creating another one. There are numerous options available, especially when searching for "jQuery fade left to right" or "jQuery fade left to right between two images."
Tips for using velocity.js
You might find the answer here: in the fade & slide section
Alternatively, check out this resource: for insights on the stagger section.