Destruction system replaces collision of mesh

When I make a destruction asset of a mesh that destructible will generated with a different collision then I defined in the mesh. I also find it very odd that you can’t see the collision in the destruction editor nor edit it in any way.

Here you can see my fool proof test, on the right is the mesh and on the left the custom collision I made. When I then make a destruction actor out of it the collision will be around the mesh and the custom collision ignored. Almost as if destruction uses the bounding box of the mesh as the collision instead. I have no idea how the destruction system generates the collision though nor can I see it. I just notice it when I suddenly collide with it whole differently as I set it up in the mesh.

36846-testcol.jpg

Hi Davison,

You pretty much nailed it with your description.

There is no custom collision for destructibles. When the destructible is created it use auto-convex collision generated for the base mesh. The fracture pieces will use the same when the mesh is fractured.

You can view the PhysX collision when simulating or PIE by using ` to bring up the console window and enter the command ‘pxvis collision’. This will show a purple collision bounds for each PhysX mesh.

Unfortunately this is not a bug, but just a limitation that has not been added yet. The request for custom collision has already been entered with UE-6140, but is currently backlogged at the moment. There is no timeline for when this will be added to the engine.

Thank you!

Tim

Ok, as it is is currently it is quite misleading. It seems there are still quite a lot of limitations to the destruction system

@Tim is there any work around to disable collision on the chunks? There has been in 4.7 and 4.8 but I am unable to find a way to replicate that in 4.9. Thanks