I am pushing each raindrop into rainDropArray, then I thought to call a function within the rainDropInterval, hmm(), and Im getting the transformation, just not the timed transition.
var rainDropArray = [];
var rainDrop;
var randomDrop;
var yourTankOverThere;
var a=0;
var rainDropInterval = setInterval(function(){
randomDrop = Math.floor(Math.random()*1000);
rainDrop =
document.createElement('div');
document.body.appendChild(rainDrop);rainDrop.style='box-
sizing:border-box;border:1px solid green;height:7px;width:7px;background-
color:green;position:absolute;top:0px;left:'+randomDrop+'px;transition:transform
10s';
rainDrop.setAttribute('id','drop'+a);
yourTankOverThere
=document.querySelector("#drop"+a);rainDropArray.push(yourTankOverThere);
hmm();
},100);
function hmm()
{rainDropArray[a].style.transform="matrix3d(1,0,0,0,0,1,0,0,0,0,1,0,0,1000,0,1)";a++}