Strange behavior of Navigation and Physics.

Development Programming & Scripting Blueprint
1

Hi all!

I found a strange behavior of Navigation and Physics for automatically generated actors. When I am changing the actor, navigation system ignores this object. And only if move it, navigation system recalculates all right. Physics simulated only for even meshes. This is steps to reproduce this behavior:

  1. Set navigation runtime generation to Dynamic.
  2. Create own actor.
  3. In the function ConstructionScript generate some static meshes.
  4. On hit event, for all meshes enable physics simulation.
  5. Enjoy strange behavior :slight_smile:

This is the video with bug demonstration (code will start from 1:20):

4

I found the workaround for those problems. But, I don’t think that is good solution. So, how to solve those problems.

Navigation:

  1. Edit - Project Settings - Navigation Mesh. Check Force Rebuild on Load.
  2. Add console command “RebuildNavigation” in BeginPlay Event.
    More info: How would I force a navmesh rebuild in Blueprint? - Blueprint - Epic Developer Community Forums

Physics:
Need create a loop that turns on the physics for all objects. Repeat until all objects will not return True in IsSimulatingPhysics.

Video with demonstration: