Hello guys,
A common workflow is to frost liquid sims that are done in fishtanks. It would be cool if when we send only the surface particles to Frost, it does some magic, like removing the faces that have normals pointing at negative Z and particles’ speed is below a threshold (and hopefully even more magical than that) so we end up with a clean water surface!
Thanks!
Like some surface contact threshold distance, great idea 
Can’t you handle this in Genome?
In your particular case, you could do both the Z normal test and a test against the original HOT surface mesh using NearestPoint, and/or check the velocity of the closest particle of your Naiad sim…
Yes, that’s what I’m doing now, I was thinking it might be faster with a shortcut for a common operation. But yes, it’s working with Genome 
Of course, it is just that it is an expensive solution for a very common issue. Not everyone owns, knows how to use, or needs all the awesomeness of genome but a ton of people use Frost.
Point taken, we have some ideas regarding this, but I cannot share yet.
I was just trying to make sure Hristo had a working solution because we were discussing his workflows out-of-forum minutes before this was posted 
And thanks for that!
I am sure you guys will think of something great
+1 for Surface Mode.
Actually I am struggling with the same issue, here. Since we do not own Genome here at the studio, I was wondering if there was maybe a different solution using Krakatoa/ Magma for doing so. I simulated a boat in a fishtank using Realflow, exported the particles as PRT and feed this PRT into Frost. Currently I am cutting of most of the lower parts of the mesh using an El Cheapo method (cull box), but I always have some of those annoying sides in the mesh. With particle normals, I could get the particles at the outer part of my particle cloud, but this is just a small victory since the top surface is also the outer part.