Buoyancy issues , physics stops when play input stops


I’m using a default character controller to mess around. I’ve made a water volume and the buoyancy stuff works while you are holding wsad and you bob up and down for another 3 seconds or so after not moving but then my pawn will freeze in place.

I’ve been ticking and unticking random boxes with no luck. Has anybody got any idea’s on how to fix this?


Nobody? Is this broken in the engine?

This does sound like a bug, I’ve logged an issue in the backlog to investigate.

I’ve had some time to take a look at this now and the system looks to be functioning as expected.
Some things to note:

  • The default settings wont create much of a ‘bob’ when in the water volume.
  • The ‘freezing’ is usually due to the ‘Fluid Friction’ value on your water volume being set too high. A value of zero will mean you don’t get any friction when moving through (and bobbing in) water, so wont freeze in place after a time.
  • I found that the following settings made my character bob up and down nicely:
    • Setting ‘Can Swim’ in your character’s movement component (nav agent props).
    • Fluid Friction of water volume: 0.0
    • Buoyancy of character: 1.4

I did find a minor bug with how collision is performed on water volumes, but that shouldn’t affect your bobbing much.
Hope this helps!