Entity converted to rigidbody with child collider doesnt receive physics

[ValonPrime]

I recently came across some curios behavior where a entity doesnt receive physics (isnt affected by gravity) when the rigidbody is added a few frames later.

1. Create a entity without a RB
2. Give that entity a child with a collider
3. Wait a few frames
4. Add the RB to the parent

Now, the entity doesn't move. Neither the child nor the parent. Using the Debug-Mode it appears that the collider is "parentless". When the parent-reference on the child is checked, it has a RB.

My expectations is, that the parent starts to be affected by gravity once the Rigidbody is added. A workaround has been suggested in the discord where a fixed RB is added from the very beginning.

I created a small example were the behavior can be reproduced: https://github.com/ValonPrime/proc_rbs_mre Notes for the Example:

• I changed the color for the Debug-Mode to better distinguish between them
• The left object has a RB from the very beginning
• The right object receives a RB when G is pressed on the keyboard
• All entities and their components can be printed to the console using the F1 key
• The before mentioned workaround has been implemented and can be enabled by setting the "DO_WORKAROUND" constant to true

Versions:

• Bevy 0.15.3
• Bevy-Rapier3D 0.29.0