This is a very cool string curtain animation on hover that can be used to do a big reveal by hiding the content behind the curtain. This was made by Three.js, verlet.js and canvas by Kevin Levron. When you hover over the strings they move around with almost real physics animation.
If you are having trouble with the pen, try the archived copy on GitHub
See the Pen What’s behind ? by Kevin Levron (@soju22) on CodePen.light