Pathfinding changes to trusses made my previously-fine navigation mesh nonsensical

[cloakedyoshi]

Reproduction Steps

1. Load the attached .rbxm (included in the private message) into an empty place, ensure that there is no baseplate below the structure
2. Enable “Show Navigation Mesh” in Studio Settings
3. Observe that the navigation mesh of the facility’s floor makes no sense, NPCs will not properly path in this building
4. Delete or move the truss beams that are above the roof
5. Observe that the navigation mesh is corrected, NPCs now path as intended

The nonsensical navigation mesh

The offending trusses

After removing the above trusses

Expected Behavior
The navigation mesh is the same with or without the above trusses.

Actual Behavior
The navigation mesh is incredibly broken, NPCs don’t know what to do. This was not the case until recent pathfinding/truss changes.

Workaround
Remove the trusses.

Issue Area: Engine
Issue Type: Other
Impact: Moderate
Frequency: Constantly
Date First Experienced: 2023-01-01 00:01:00 (-08:00)
Date Last Experienced: 2023-02-01 00:02:00 (-08:00)
A private message is associated with this bug report

[sicknoobie (Marioman73)]

The odd part is that trussparts can deform the navmesh even if they’re suspended hundreds of studs in the air above any ground. Can also confirm that the messed up navmesh causes issues as my NPCs get very confused sometimes due to this issue. (Especially in small rooms)

[oldmannt]

We’re working on this issue. Hopefully, we will release it soon.

[sicknoobie (Marioman73)]

PathfindingNEARTrussDemo.rbxl (59.2 KB)
Here’s a repro file for an issue that COULD be related to this. It seems to mostly occur when near truss parts so I’m assuming it’s related.
Edit: Can confirm it’s due to the navmesh being screwed up by the truss parts.

NPC basically gets stuck moving in one spot because a billion nodes appeared there or something. It’s trying to move up a non-existent ramp.

[oldmannt]

@cloakedyoshi this issue has been fixed. I was trying to get attached.rbxm you metioned, but I couldn’t find it, did you upload it.

[oldmannt]

You’re right, it’s related. We deployed the fix this Monday. I tested the repo PathfindingNEARTrussDemo.rbxl you uploaded. The NPC isn’t blocked any more.

[cloakedyoshi]

It’s attached using the private section of the bug report. You might need special perms to see it perhaps, I’m unsure.

In pulling up the affected navmesh, it appears to indeed be solved though:

Thank you!

[sicknoobie (Marioman73)]

Can confirm it’s also fixed on my end. Thanks again for your help in the improvement of pathfinding service. Looking forward to see what other changes and additions you make in the future!