Unreal Engine Navigation System Guide: Directing AI Agents

Unreal Engine’s official documentation describes Navigation System as the system that enables AI agents to find their way through a level. For teams creating architectural presentations, interactive interior experiences or real-time visualization scenes, the central idea is to define where agents can move and how they choose a route to their destination. The documentation does not specify a particular Unreal Engine version, so this guide covers general concepts that are not tied to a version number.

1. First, understand how the navigation network works

Navigation System uses the level’s collision geometry to generate a Navigation Mesh. The mesh is divided into tiles, which are in turn split into polygons that agents can use for pathfinding. The system evaluates the polygons as a graph and searches for the route with the lowest total cost, taking into account the cost assigned to each polygon.

That means a route is not simply the geometric distance between two points. An area’s cost affects whether an agent prefers to travel through it. For example, if visitor agents in a presentation scene need to follow a particular route, cost logic can help shape how that route is selected. However, the documentation does not provide fixed cost values or recommendations for which values suit a given project; values should be assessed according to the purpose of the experience.

2. Choose a Navigation Mesh generation mode

The documentation lists three generation modes: Static, Dynamic and Dynamic Modifiers Only. These modes determine how the project generates the Navigation Mesh and which options are available. The source description does not explain the modes’ detailed behavior or specify which one to choose for different scene types. When deciding, check the project’s mesh generation needs and consult the official documentation for the relevant mode.

A basic workflow could look like this:

1. Identify the level agents will use. Because the navigation network is generated from the level’s collision geometry, review how the scene geometry relates to the areas agents can move through. Don’t assume that every surface that looks walkable will automatically be a valid navigation area.

2. Choose an approach to Navigation Mesh generation. Consider Static, Dynamic or Dynamic Modifiers Only based on the project’s needs. Don’t infer the modes’ details from their names alone; consult the official descriptions.

3. Inspect the areas covered by the mesh. Since the mesh is divided into tiles and polygons, check whether the areas agents are expected to reach are represented in the navigation network.

4. Review route costs and connections. Keep in mind that polygon costs affect route selection. It is also possible to connect areas that are not adjacent, such as platforms or bridges, on the Navigation Mesh.

5. Handle moving obstacles separately. If agents need to avoid dynamic obstacles and other agents while moving, look into RVO or Detour Crowd Manager.

3. Set up the character with movement and animation components

Unreal Engine documentation describes Character as the Pawn class extended with specific components. Character includes CharacterMovementComponent, CapsuleComponent and SkeletalMeshComponent. This distinction matters when designing a moving agent in a visualization: pathfinding should not be considered separately from the character’s movement and collision representation in the scene.

CharacterMovementComponent supports movement such as walking, running, jumping, flying, falling and swimming. The documentation states that this component includes properties related to walking and falling friction, movement speeds on land, in air and in water, buoyancy, gravity scale, and the forces the character can apply to physics objects. You don’t need to change all these values in every scene; the goal is to make character movement consistent with the design of the experience.

CapsuleComponent is used for movement collision. CharacterMovementComponent’s calculations for complex movement geometry rely on the assumption that the collision component in the Character class is a vertically oriented capsule. As a result, the character’s visible model and collision representation may differ; when investigating pathfinding and movement issues, looking only at the SkeletalMeshComponent’s appearance may not be enough.

SkeletalMeshComponent represents the main skeletal mesh used for advanced skeletal animation. Character-derived classes can also include additional Skeletal Mesh components. However, the main character skeleton’s movement and animations are handled through this component.

4. What should you consider in architectural and archviz workflows?

In an interactive architectural experience, Navigation System can be useful when visitor agents need to reach destinations in an interior or landscaped environment. The first checkpoint is ensuring that the navigation network matches the actual scene geometry and collision representation. If an agent can’t reach a target, the cause may not be the pathfinding algorithm alone; check both whether the network covers the relevant area and how the character’s movement components are configured.

Epic’s documentation also points to separate topics such as modifying a Navigation Mesh, custom navigation areas and query filters, Navigation Invokers, optimizing generation speed, using different mesh resolutions together, and using navigation with World Partition. These are topics to consult at a more advanced stage. However, because the current source summary doesn’t provide detailed settings for these features, it wouldn’t be appropriate to recommend a specific configuration or value. Similarly, automatic connections between meshes and extending pathfinding with Navigation Components are listed as separate guides in the official documentation.

Common mistakes

• Assuming that because a visible model looks walkable, the Navigation Mesh covers that area.

• Overlooking the effect of polygon costs on route selection.

• Treating avoidance of moving obstacles and other agents as something that can be handled with the basic navigation network alone.

• Guessing at mode behavior, default values or menu paths that aren’t provided in the source material.

Inspecting the mesh, targets and character movement separately in an initial test makes it easier to identify which layer is causing a problem. Epic’s Navigation System sample project includes example levels covering different guides and can be used to compare the basic workflow.