jQuery Forum

You haven't stated what you are really trying to accomplish, nor exactly what kind of "smooth/ease" you want. Do you want the boxes to move/slide? Or do you want them to transition the color? Or both? Or something else? Is there some example you can point to on the web?

And jQuery is not a good solution for animation in any case. It was several years ago, when CSS animation did not yet exist.

I think you can do this with pure CSS. Make destaques position:relative, and each destaque position:absolute. Then animate the positions and/or colors with CSS transitions/animation. You don't need a setInterval to loop transitions. It can be done in CSS.

There are hundreds of sites that will teach you all the tricks you can do with CSS today. So many designers like to show off their techniques! I like the CSS-Tricks site, but there are many, many others. MDN is good for detailed documentation.

The basic technique is to use a position:relative base node and position:absolute items, then manipulate CSS of the items. You need to position one over the other if you want to fade, or in starting position for movement effects, and then apply CSS transitions.

The plugin you found does this, supports a wide variety of effects and options, and seems to work well. Is there some reason you don't want to use it? Did you try it?

It is a bit old, and hasn't been updated in 3 years. There are certainly other similar plugins that are currently maintained. I would suggest you search for a newer/more maintained plugin. I'll bet you find a dozen. 

A more modern plugin might utilize CSS flexbox to create the basic grid layout at load time, rather than JS doing pixel calculationsYou might have to be a bit creative to come up with search terms - I tried "brady bunch effect" but I didn't have much luck with that! ;) Figure out what designers call this... try e.g. "random image shuffle grid js css plugin"

If you want to do it yourself as an academic exercise, you can look at the source code of the plugin, and use it to make your own plugin more suited to your own needs, or just get some ideas from it.