Why Your Unity NavMesh Agent Won't Cross That Gap

Baked NavMesh only connects walkable surfaces that physically touch each other. The moment there's a gap, a drop to a lower platform, or a ledge, agents treat the edge as a wall and simply stop, even when the crossing is obviously possible from a design standpoint.

Off-Mesh Links solve this. You place one link point on each side of the gap and connect them:

csharp
// Runtime example: check if an agent is currently on an off-mesh link
if (agent.isOnOffMeshLink)
{
OffMeshLinkData data = agent.currentOffMeshLinkData;
// trigger a jump/climb animation, then call agent.CompleteOffMeshLink()
}

Once connected, the NavMesh treats that gap as traversable, and you control what actually happens when the agent crosses it, a jump animation, a drop, a climb, whatever fits the movement.

Easy to overlook because the NavMesh bake still succeeds without them, it just quietly excludes any area that needs one. If your AI is avoiding a route that should obviously work, this is usually why.