Mass Navigation in UE 5.4

The UE5 Mass Entity system includes Navigation-specific fragments and processors you can use in your game without recreating the wheel. It bundles all of this code into the optional MassNavigation module in the MassAI plugin.

In general this class is not well documented as of UE 5.4 and is under significant development. This considered, the code is well written and follows common patterns that you will learn as you read.

In standard Mass methodology, the Traits/Fragments define the data required to move the Entities. The Processors execute once per simulation cycle to update the data.

MassNavigation Traits

• UMassObstacleAvoidanceTrait
• UMassNavigationObstacleTrait
• UMassSmoothOrientationTrait
• UMassSteeringTrait

MassZoneGraphNavigation Traits

• UMassZoneGraphNavigationTrait

MassNavigation Fragments

• FMassNavigationEdgesFragment
• FMassSteeringFragment
• FMassStandingSteeringFragment
• FMassMoveTargetFragment
• FMassGhostLocationFragment
• FMassNavigationObstacleGridCellLocationFragment
• FMassAvoidanceColliderFragment

MassZoneGraphNavigation Fragments

• FMassZoneGraphPathRequestFragment
• FMassZoneGraphLaneLocationFragment
• FMassZoneGraphCachedLaneFragment
• FMassZoneGraphShortPathFragment
• FMassLaneCacheBoundaryFragment

MassNavigation Processors

As of 5.4 a search for all Mass Processors (any class derived from UMassProcessor) in the MassNavigation module reveals:

• UMassMovingAvoidanceProcessor
• UMassMovingAvoidanceProcessor
• UMassSmoothOrientationProcessor
• UMassSteerToMoveTargetProcessor
• UMassOffLODNavigationProcessor
• UMassNavigationSmoothHeightProcessor
• UMassNavigationObstacleGridProcessor

MassZoneGraphNavigation Processors

• UMassZoneGraphPathFollowProcessor
• UMassZoneGraphPathFollowProcessor

MassNavigation Observer Processors

• UMassMoveTargetFragmentInitializer
  • Sets the move target to the Entity’s current Transform location (e.g. already at goal of current location)
• UMassNavigationObstacleRemoverProcessor

MassZoneGraphNavigation Observer Processors

• UMassZoneGraphLocationInitializer