AI Navigation fails with navmesh set to Dynamic runtime generation

I’m having trouble moving an AI character to another actor when runtime generation is set to dynamic. It works if I set it to static, but gives an Aborted error otherwise. I can see the cell updating when I start the simulation, changing from green to red and back to green. I assume the update triggers an error, and then in the visual logger the RecastNavMesh throws a warning: FPImplRecastNavMesh::InitPathFinding start point not on navmesh.

Am I doing something wrong?

I have a large equipment traveling and AI character moving on correctly only before it moves. I think the navmesh is not updating correctly. Have you found the solution for your case?

I had a similar issue to this one and I fixed it. I had a collider on my pawn that had “can effect navigation” set to true, and I had it blocking navigation. My thought process was that this would prevent pawns from running into each other. The problem was that the collider meant that the pawn blocked its own starting point in the navigation. The way to fix this was to get rid of anything on the pawn that would affect the nav mesh and to instead go to the movement component and turn on RVOavoidance and set the radius for the character pretty high. Hope this helps.

I took off Dynamic Obstacle on the capsule of the ThirdPersonCharacter.
In the editor the dynamic navMesh looks green but in simulation keeps red in several places and the character does not move. With static navmesh all works

I even deleted the character from the scene and the mesh remains red without doing any movements of the machine.

Looks like you may have a different problem than the one that started this topic. I suspect something is up with the settings on your nav mesh. Does this only happen with run-time generation set to dynamic?

exactly, only on dynamic

Bump, I’m having the same issue. My ai moves very weird with the Navmesh set to dynamic.

have the same problem. seems to me like dynamic naymesh generation ignores all generation settings (ProjectSettings and RecastNavMesh) and replaces them with some default settings (e.g. always Agent Radius 35).

Just found a solution for my problem, posted by almighty mieszko: Navmesh Character Radius - Character & Animation - Unreal Engine Forums

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Somewhat related, hopefully this helps someone else.

For me it was making sure nothing (static meshes) attached to the character (armor, weapons, torches, etc.) that have “Can Ever Affect Navigation” checked.

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after researching the engine code, I found that in the PathFinding() function from recast nav mesh, there is: Query.findNearestPoly() which check if poly exists in some extents near navigation in the start point when your character trying to find a path.

for example, by default it can’t find StartPoly if navdata turned out to be significantly lower / higher than the surface on which the character stands.

fortunately, you can easily expand this extent in the ProjectSettings/NavigationMesh/Query - VerticalDeviationFromGroundCompensation

Uncheck “Can Affect Navigation Generation” in Class Defaults AND Uncheck “Can Ever Affect Navigation” in all Collision of all Components of AI.

Dynamic mode generate navigation every 0.5 sec (by default in Project Settings > Navigation Mesh) so that’s why “Can Affect Navigation Generation” making this problem !
(Worked for me)

Hope it will help !

PS : Maybe it could fix FindPathToLocationSync nod…