Hit Events not triggered for Actor with Physics enabled

Development World Creation
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1

I have a very simple BP actor, with only one Destructible component, nothing else. That component has “Simulate Physics” flag on, as well as the “Simulation Generate Hit Events” flag. Collision preset is set to custom, with collision enabled for query and physics. It blocks the game map terrain.

Now in the game, when this actor is being spawned, it correctly falls down to the terrain and stops there, so collision is correctly detected. However, neither the “OnComponentHit” event of the component nor the generic “Event Hit” events are being triggered when that actor touches the ground.

Any ideas what I might be missing here?
Is this a bug or a feature?

2

Is a feature… Both meshes need to have the flags activated in order to trigger the Hit event.

But if the problem persists try this:

Make the BP from a Static mesh placed on the map, like a cube, instead of making a simple BP actor. Maybe that could fix your problem, worked for me with the movement with keys.

3

Thanks for your reply. But I cannot set the flags on both meshes, as the other mesh is a landscape, and that has no such options as to generate hit events :frowning:

4

Hi haimat,

Thank you for the report. I was able to reproduce this and have entered JIRA UE-34420 for the developers to investigate further.

As a workaround, you can enable Impact Damage on the Destructible mesh and it will register the hit on the landscape. However, you will have to set the mesh up to not fracture on the first hit if that is what you want.

If you need more info on how to set that up, check out this Destructible showcase from Tim Hobson.

Cheers,

TJ

5

Thanks for the feedback!

6

Hey, im struggling with the same issue. Have you found a solution?

7

Not really :frowning:

8

This is still very much an issue. It seems like the OnComponentHit Event for Destructibles stopped triggering in 4.13

  • 4.11 - Working
  • 4.12.5 - Working
  • 4.13 - Broken
  • 4.14 - Broken

Very simple to test :

  1. Import any mesh
  2. Right Click → Create Destructible
  3. Fracture
  4. Right Click DM → Asset Actions - > Create Blueprint From This Asset
  5. Add OnComponentHitEvent(Destructible)
  6. Add Print String
  7. Turn on “Simulation Generates Hit Events” for both the DM Component and floor plane
  8. Turn on Simulate Physics for DM Component
  9. Simulate or Play

121614-dmhiteventbp.jpg
121614-dmhiteventbp.jpg1161×1057 187 KB

Can we get a word from Epic as to whether this is due to an actual issue/bug or whether the workflow for this has changed?

Thanks

9

Apparently checking the Enable Impact Damage checkbox in the destructible settings allows the OnComponentHit event to be triggered.

10

Im on Unreal Engine 5.2.1. I couldn’t get skeletal mesh’s to return hit or overlap triggers. They interact with the world but don’t those nodes don’t trigger even when the object the hit also has generate hit events and overlap events on. They do work if it’s a static mesh though. I was able to turn my skeletal mesh into static mesh and proceed but still annoying.