[4.11] Collisions in hierarchy below Scene Component


What I am asking/writing here is being written under bug report as this is not what I would expect from the behavior of the following component: Scene Component.

So, my question is:

Is there any way to have components in the hierarchy below a Scene Component have collision capabilities?

Steps to repro:

  • Create new FPS project with starter content
  • Create new blueprint
  • Add Cube component as root
  • Enable physics simulation on root
  • Add Cube component as child
  • Separate them by a distance great enough so that the center of mass is between them
  • Place new BP in world

Now. Press Simulate. See how the two cubes will hit the ground and bounce. Great. Rotate it if you really want to see the effect correctly.

NOW, let’s talk about what’s wrong.


  • Insert Scene component between root and second Cube component
  • Make sure that the second Cube Component is child of Scene Component

Now… Press Simulate again… Ohh… The cube that’s under the scene component falls under the ground…

If you want to really see how wrong this is…


  • Add a third Cube that a direct child of the root.
  • Displace it enough on another axis
  • Make sure that the center of mass if somewhere in the middle of this triangle of cubes

Now… Press simulate again! The first and third cube will collide while the second cube will go through the ground…

I don’t see how we can use the Scene Component as a way to order and hierarchies our object when it breaks the collision for all its childs.

Scene Components should not stop collision propagation from the root to the leafs of the tree.

If this is the behaviour intended, please, let me know of another way to have dummies to use to make a hierarchy and potentially offset groups of components…
If this behaviour is not intended, please do something as soon as possible about it or give me some leads as to what could change that since this is a real pain and I would be ready to invest myself into fixing it if needed.

Best Regard,

Hello Erio Hayaweh Maondial,

I was able to reproduce this issue on our end. I have written up a report (UE-30895) and I have submitted to the developers for further consideration. I will provide updates with any pertinent information as it becomes available. Thank you for your time and information.

Make it a great day

Hi Rudy,

Thank you for confirming this to me. :slight_smile:

Have a nice day!