Hi, first of all I wanted to thank you all because both your paper and the slides are super high quality stuff, it's by far the best source of documentation I could find on SPH.
I'm implementing SPH following your paper and the slides for my game, and I noticed in the slides that there was what I believe to be a typo :
It is in the first set of slide, sheet 6.11.

According to your paper, the velocity update is actually adding the pressure force, not subtracting it :

From my tests, subtracting the pressure force means that particles attract each other which is unwanted behavior, so I assume the correct velocity update is by adding the pressure force.