@caskal,@Andrea, Dear Guys, I have the same problem with the 2nd video you posted, it looks like the velocity it is gone after the whitewater sim started, but I checked my whitewater source and flip compress cache note, there are velocity attributes. and I use the compress as the emitting source, but still got this problem, do you guys know or how do you fix this problem? cause this is my first time to try the H17 whitewater. I am so confused. I am going to update the pic or playblast here later today. thank you so much in advance!!