Multiple Pontoon on Buoyancy not working

Development Rendering
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1

Hi, I recently installed Unreal Engine 4.26 and tried to use the new water volumes with buoyancy and for some reason as soon as I add more than one pontoon, the buoyancy seems to no longer apply.

Is there something that I am missing for it to work?

I tried copying the exact testing tube from water volumes and it does the same. If I add another pontoon it sinks instantly and does not even get affected by the water in any way.

Edit:
Apparently if I turn the boat upside down it works now?

2

Fixed by making the boat appear above water ^^

3

I’m stuck with the same problem loosing all day for solving this. Whenever i was adding third pontoon, the buoyancy are stopped work and object sinks. I figure it out that for some reason whenever a simple cube are used then there cant be added more than 2 pontoons. But when i replace that mesh (Cube) with mesh (EditorCube) then everything are starting to work properly.

4

Hi ^^, I’ve discovered recently that the objects spawned inside the water volume will sink instantly and buoyancy won’t be taken into consideration if there are multiple pontoons for some reason.

I fixed it by making sure it was above the water and it dropped into the water. The same way we see the boats spawn in Sea of Thieves for example.

So far doing this method made it so I can add as many pontoons as I want or at least so far I’m at 26 pontoons and it’s still not failed me other than trying to figure out how to get my boat not to go sideways now due to weight :stuck_out_tongue:

Also, make sure the radius on your pontoon is high enough. Too much weight on it will make it sink regardless of if you spawned it correctly or not.

5

this can be fixed by enabling ‘generate overlap events during level streaming’ on the water body, otherwise water won’t collide with actor if it starts within volume

6

Hey et al,

I had the same issue. Here are some things I noticed in UE 4.26.2 after an hour or two of playing with the Buoyancy Component.

  1. A Physical Object has to be the root of your BP for buoyancy to work. (ie Static Mesh, Box Collision, Cube, etc)
    [A Scene Component as the root object will not work]
  2. If Box Collision or Cube is root, up to two pontoons are supported. When I add the third, it sinks immediately
  3. If Static Mesh is root, > two pontoons are supported. I don’t know how many, but I have 4 working just fine on a raft I made.

So, in essence, make sure you setup Static Mesh as your root. Correctly add your colliders on your static mesh (and not using Box Collision in BPs like I was trying to do). Enjoy your floating buoyant objects! :slight_smile:

And yes, objects starting above water seems to be essential too, but i didn’t play too much with that.

7

Hi. I am having this exact issu in unreal engine 5 now. I can get engine static meshes to float on sveral pontoons, but when i import a box from sketchup, i can only use two pontoons. I have my sketchup cube static mesh as root, with convex collision, actor above the water when simulating but it is still not working. Any ideas

8

G’day,

This is really a reply to anyone trying to figure this buoyancy out.
I have been strugglying with this problem with a simple box shaped vessel that i want to float on my ocean.
The issue was that it would spawn above water, hit the ocean surface and suddenly either sink to the bottom really fast (in a negative buoyancy) or would shoot into the sky and litteraly despawn.

I found that when i used 2 pontoons it would be ok (but the ship would flip over due to balance). If i used 4, these errors occured.

The error started due to my use of using the ‘sockets’ as the location variable. When i manually copied the location into the coordinates, then this error disappeared.

Also, a key issue is making sure your pivot is at the centre of the mesh.

I know this is late for the response to this issue, but I literally struggled all day and hope to save someone some time in the future.