Hot realoding break navigation paths through custom NavArea

Development Programming & Scripting C++
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1

If I hot reload a module containing custom nav areas even if I don’t make any modify to these NavArea classes the nav igation system will not generate paths through them any more.

NavlinkProxy connection color changes from the custom NavArea’s assigned color to black.

Changin navlinkproxy nav area to default area make the connection work again but changing back to custom doesn’t fix the problem for custom nav areas.

The only solution seems to restart the editor.

2

Hi Deadlineproof,

I tried to reproduce this issue in a test project using a simple custom nav area class, but was unable to see the results that you described. Would you be able to provide some more information about the issue?

  • What version of the Engine are you using, and are you using the binary version installed by the Launcher or did you build it from source code?
  • Are you making any specific changes to your custom nav area class?
  • Where are you making changes to need a hot reload?
  • Does this only happen to you in your own project, or does it also occur in a new project?
  • Was your project originally created in the version of the Engine that you are currently using, or had you upgraded it from a previous version?
3

version was 4.7.0 binary, now i’m using 4.7.2 , but i’m not working on pathing and I’m not using hot reloading as I’m now mainly using blueprint at moment so I didn’t check if it has been fixed.

Area class just set a bit in the flag bitfield.

Changes was made in other classes like a custom pawn and relative custom movement controller , but i don’t have problem with these classes navigating the mesh but globally the path is not available any more if the area is set.

I didn’t check on a newer project I can do it tomorrow and let you know.

the project was originally created on 4.7.

thanks , I will provide you with further data.
I hope that meanwile the problem has been solved (4.7.2 /promoted/master)

4

Hi Deadlineproof,

We have not heard back from you for a few days. Do you still need any help with this issue? I will be marking this issue as resolved for tracking purposes, but please feel free to re-open it at any time if you need any additional help.

5

I have the same issue described by op (source build 17.2). It makes hot reload practically unusable when a custom NavArea class is in the game module, because it messes up custom links in the navmesh of the map.

To reproduce:

  • Follow AI jump tutorial, making a map with some NavLinkProxy with the NavArea_Jump: ( A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums1-_Making_AI_Jump_as_a_Part_of_Path_Following ). Put some distinguishable DrawColor in the constructor of UNavArea_Jump: UNavArea_Jump::UNavArea_Jump(const class FPostConstructInitializeProperties& PCIP) : Super(PCIP) { FNavAreaHelper::Set(AreaFlags, ENavAreaFlag::Jump); DrawColor = FColor::Magenta; }
  • Generate the navmesh in the level, so that when showing paths you can see the custom links with the custom color
  • Do a hot reload
  • Delete the RecastNavMesh-Default actor from the map (if present)
  • Do a paths build: now custom links are black. When the AI tries to traverse the jump links, the jump area flag is 0.
6

Hi matfer,

Sorry for not getting back to you on this. Are you still having trouble with this issue? If you are, we now have a new method for reporting Engine bugs. Please visit our Report a Bug page and fill out the form there with as much information as you have available.