So awesoooooome! Loving the slow but steady polish this series is getting. And all at a solid 60fps I assume. Delicious! I hope there will be some kind of campaign co-op - and with hit markers this time please!! (Totally biased opinion is biased :D )
Basically it takes the screen UV in 0>1 space, biases it to -.5>.5 space, scales it using the depth of the scene at that pixel, biases it back (unnecessary) and then scrolls it horizontally and does a crude faded vertical line (using a texture would be much better)