In the Steakhouse theme we have implemented the animation engine based on the scrollReveal.js script. This script makes creating elements onscroll animations very simple to define.
Thanks to this script you can describe an animation using natural language.
Description of the animation is placed in the data-scroll-reveal attribute:
<!-- These 2 lines are equivalent --> <p data-scroll-reveal="enter top move 25px"> foo </p> <p data-scroll-reveal="enter from the top and then move 25px"> foo </p>
The full description of the syntax is available on the project documentation page