Why does my NavMeshAgent take an expensive route over a cheaper one?

Area costs are configured per-agent on its Area Mask + Cost arrays. If the agent's cost for the link's area is the default 1, expensive paths look cheap. Set agent.SetAreaCost(areaIndex, highCost) and the pathfinder respects it.

How do I set up Area Types?

Window → AI → Navigation → Areas. Add named areas (Walkable, Jump, Swim, Sneak). Each has a default cost. Per-agent cost overrides via SetAreaCost(area, cost).

Where do I assign Area to a NavMeshLink?

NavMeshLink Inspector → Area Type. Drop-down lists your defined areas. Set per-link so jumps and ladders carry the right cost.

Fix: Unity NavMeshLink Area Cost Ignored by Agent

Quick answer: Define area types in Navigation Areas. Assign Area Type on each NavMeshLink. Set per-agent cost via agent.SetAreaCost(area, cost). The pathfinder weights paths by cumulative area cost, picking cheaper routes.

You add a Jump link from a high ledge to the ground. Set the link Area = Jump with cost 5. AI still takes a long way around. Costs need both the link tag and per-agent overrides.

The Symptom

Agents either always use a NavMeshLink (you wanted them to avoid) or never use it (you wanted them to prefer). Default Area Walkable with cost 1 means everything looks equally cheap.

The Fix

Step 1: Define area types. Window → AI → Navigation → Areas tab.

Walkable: 1
Jump:     5
Swim:     10
Sneak:    15

Default costs apply unless an agent overrides.

Step 2: Assign on the NavMeshLink.

NavMeshLink Inspector:
  Area Type:    Jump
  Bidirectional: true
  Auto Update Position: true

Step 3: Per-agent cost override.

public class AgentInit : MonoBehaviour
{
    NavMeshAgent agent;
    void Start()
    {
        agent = GetComponent<NavMeshAgent>();
        agent.SetAreaCost(NavMesh.GetAreaFromName("Jump"), 3.0f);   // this agent prefers jumping
        agent.SetAreaCost(NavMesh.GetAreaFromName("Swim"), 100f); // this one avoids water
    }
}

Path Visualization

Window → AI → Navigation → Areas. Tick “Show Areas” in the Scene view. NavMesh chunks color by area type. Confirms link covers the intended span.

Verifying

Spawn the agent, give it a target across the link. With a low Jump cost, agent uses the link. With a high cost, agent walks around. Tune by trial.

“Areas defined. Link tagged. Per-agent cost. Paths reflect preferences.”

Related Issues

For NavMeshAgent stuck, see NavMesh corner. For multiple agent types, see multiple agent types.

Tag links. Tune costs. Paths bend.