Can a buoyancy actor float on water body custom?

i tried to make a buoyancy actor float on Water body Ocean, and it worked.
but it does not work with Water body custom. Is it possible to do it in this way? If not possible, how can i make a small piece of water element just like what in a bathtub?

The ue Documentation states that “custom are not rendered using the Water Mesh Actor, nor do they affect the landscape”, is it the reason?

I’ve also found that the buoyancy example provided by UE doesn’t work when used with custom water.
It falls to the bottom as if it were a normal physics cube.

I’m also interested to know if this is intended. If so, there is any way to add this interaction back into custom water?

As of 4.26.2 buoyancy has started working with water body custom. We had to recreate the water body customs from scratch, then it started working.

Having a similar problem with custom water body and flotation but in UE5.
Is this a bug and if so will it be fixed in the foreseeable future please?

The Buoyancy component is reading the wave height from the Water Body, so it won’t work out of the box with another water mesh/plane. You’d have to edit the Buoyancy component to read from your water source instead.

Question asker is specifically asking about “water body custom”. To confirm for anyone else ending up here “water body custom” does/should work with the ue4 buoyancy example out of the box.

To get the Water Body Custom working, you need to use a mesh that is not just a plane. Use a cube for example. I recommand to use a cube with a pivot point on the top face, because the buoyancy component use the pivot of the overlapping water body mesh as base. Only if it’s overlapping the mesh, it uses buoyancy.

Hope that helps! :wink:

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Thank you everyone for your advice. What i’m trying to do is make my water lilies float on the lake :slight_smile: I’ve turned them into actors and they drop under gravity when in play mode… but as mentioned, they just fall too the bottom.

Hello,have you solved it? I wanted the boat to float in a lake in someone else’s map environment, but using the buoyancy plugin didn’t work. Do you have any ideas?

How did you get cube shaped water? When I use Water Body Custom, its just a plane.

Not to necro a post but I would really like to know how you did this. As I can’t figure out how to assign a custom water body to a static mesh.

  • set water mesh override like the last reply
  • set collision of water on OverlapAll

Now the BP_BuoyancyExample under Engine > Plugins > Water Content > Blueprints work very well.

Move it on content folder you prefer. Edit it with your custom mesh. Edit mass end play with bouancy value, watch a tutorial on youtube.

A good trick is edit the mesh with blender 3ds or other and move it up and down to change the pivot point.
For example moove the upper zone of a barrel in the 000 cordinate of 3ds. Or move the down zone of a inflatable in 000 cordinate.

I realize a flamingo inflatable in a pool and moove the pivot of few cm change the result drastically.

Sorry for my english.

on water mesh override, my cube10 I just made for under custom water, isn’t showing up. Now what :wink:

doesn’t work in 5.3.

I’m also struggling with this in 5.3.2. I got the buoyancy working with custom water body with the help of above instructions. I can use the “WaterBodyCustom” collision as “WaterBodyCollision” opposed to suggested “OverlapAll”. But it is not completely free of issues.

I believe the key is that “Water Mesh Override” has to be an actor with Z-dimension, so not just a plane. I’ve used a scaled “EditorCube”.

After you have added the mesh with enough Z dimension, you can add for example the “BP_BuoyancyExample” to see how it works.


  • The floating BP has to be completely above surface before the simulation starts. Otherwise it will just drop to the bottom.
  • When using the “WaterZone”“Use Far Mesh Without Ocean” the seam between “WaterBodyCustom” and ocean is visible. The WaterBody will move in waves up and down, but the ocean stays in same position. It is not that visible from far if you set the WaterBody’s top just above the ocean. But if you look from the ocean side it is very visible.

For anyone having any issues with changing the Water Mesh Override for Water Body Custom, changing the height of the actor’s spline seemed to fix all problems. After changing the water mesh, I noticed that objects would only begin to float while falling halfway through the mesh. If you move the camera inside the water mesh, you can see where the underwater post-process begins. Going to the WaterBodyCustom actor and doing “Select All Spline Points” and adjusting their Z location until the post-process starts just under the surface fixes objects that would fall through the mesh. Hope this helps someone.