I think it has something to do with the depth of field on the camera chopping off rain particles, plus TSR or anti-aliasing. At least with 5.5 we can render out holdout passes on the shot, thank goodness, because I’m going to have to bring this into After Effects and put rain in after the fact. Big bummer, should be able to render particulate like this from UE, that’s like, a huge selling point is the rain interacting with the surfaces. Let me know if y’all sort anything out.