In a game I'm making in LibGdx, I wish to incorporate a ripple effect. I'm confused as to how I get access to the individual pixels on the screen, or any way to influence them (apart from what I can do with sprite batch).

I have my suspicions that I have to do it through openGL, and it has something to do with apply a mesh? This brings me to my question, what exactly is a mesh?

I've been working on my game for about half a year, and am doing great with the other aspects of the game, but I find this more advance stuff isn't as well documented.

Thanks!