Physics Objects under water

Hi All I hope I’m posting this in the corrects place as there isn’t a section just for physics.
I’m working on an under water project in blueprint and I’m having some problems with physics objects and character movers.

If I have a cube and give it a mass of 5000 and gravity takes it to the bottom I cant push it.
The same cube but without gravity so it floats and it moves like it has no mass.
The same cube with gravity but neutral buoyancy so it floats and the same again it moves like it has no mass.

The cube is a static mesh with simulate physics turned on and the Character is moved with Add Movement Input

Is there some setting in the physics material or the simulation that I may be missing?
Do I need to use a different movement node for the Character?

I hope someone can help.


I do not think you can use any movement node, set Location node or similar in combination with physics. Back a few version UE4 even crashed when you used a Set Actor Location node on a physics enabled actor, because the ‘magic’ setting to a new location would mess up PhysX.
If you want to move the cube with physics on, then apply a force to move it, so that everything is handled by PhysX. For example, the cube floats and you want to move it along the x-Axis, then apply a force along the x-Axis to move it and so on. Then you feel the mass.

The boxes have no movement node they just have physics and are moved by force but when I bump into them with a Character that has a movement node, when there on the floor they stick like they have mass but when they float they have no mass and can be freely pushed around. This even happens when I have two floating physics object bumping into each other.

I see. Then it is hard to tell why this happens without looking into a small project that reproduces the issue.