Collision of child actor doesn't rotate if the parent is simulating physics

Collision of child actor doesn't rotate if the parent is simulating physics. This was an old bug that an AnswerHub user reported back in 4.9 but now a licensee is reporting this same behavior in 4.18.

 

 

1. Open the attached project
2. PIE

Results: Case 2, where a rotating object as attached to a physics object, the collision will not follow the attached object

Expected: For the collision to follow the rotating object and interact with the ground and other objects

 

Old AH repro steps:

1. Open the attached test project
2. Once opened, PIE
3. Click to get focus, move the mouse to rotate the gun component (pipe)

4. The gun will rotate but will not collide with the physics boxes

5. Move the 'tank' with WASD and ram the boxes (the collision seems like it is still in the starting position for the gun component)
6. Exit PIE
7. Open the 'BP_Tank03' blueprint
8. In the Components tab, select Body
9. In the Details panel > Physics > Disable 'Simulate Physics'
10. Compile
11. Back in the editor, PIE
12. Click to get focus, move the mouse to rotate the gun component (pipe)

13. When 'Simulate Physics' is disabled on the parent component, the collision of the child works fine

Results: The gun will rotate but will not collide with the physics boxes if the parent is simulating physics

Expected: For the gun to collide regardless of if the parent is simulating physics or not