Summary
When entities are spawned at runtime using SceneGraph, the NavMesh does not properly update. In some cases, small navigation fragments are generated on the floor, but these are inconsistent and partial, never covering the full geometry. As a result, AI cannot reliably navigate inside or around dynamically spawned structures.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
AI
Steps to Reproduce
Create an NPC with Behavior
Place this NPC in the island and confirm that it navigates correctly on the initial NavMesh.
Make a simple Verse script to spawn a prefab entity via SceneGraph after at least 5 seconds of runtime.
Expected Result
When a prefab entity is spawned dynamically via SceneGraph, the NavMesh system should rebuild or extend automatically to account for the new geometry.
The generated NavMesh should fully cover floors, corridors, and navigable surfaces inside the prefab.
AI agents spawned on or near these entities should be able to:
Recognize new obstacles (e.g., walls, props) as blocking navigation.
Generate valid navigation paths across newly added walkable surfaces.
Observed Result
The NavMesh does not fully update after entities are spawned.
Occasionally, small isolated NavMesh fragments appear on the ground, but coverage is incomplete and inconsistent.
AI agents continue to treat most of the new space as if it were empty.
Bots physically collide with the new walls and props, but no valid navigation paths are generated through the runtime-built structures.
Platform(s)
PC