Adjusting navmesh resolution

If you for example need to have one part of the navmesh higher detail than other parts.

Available in Unreal Engine 5.3

Get NavigationSystem in C++

auto NavSystem = FNavigationSystem::GetCurrent<UNavigationSystemV1>(GetWorld());


  • OnNavigationGenerationFinishedDelegate: Runs whenever navmesh is regenerated, this includes things like when NavArea data is changed for navlinks or other things


Querying from C++ requires FNavAgentProperties. Pawns and such have them, but if you want to get them by agent name (such as how it’s defined in project settings), you can instead use FNavDataConfig which extends it.

auto* NavSystem = FNavigationSystem::GetCurrent<UNavigationSystemV1>(GetWorld());
const FNavDataConfig* NavDataConfig = NavSystem->GetSupportedAgents().FindByPredicate([this](const FNavDataConfig& NavDataConfig)
	return NavDataConfig.Name == DesiredAgentName;

Common issues

  • Actors that use navigation should have “can ever affect navigation” turned off. If turned on, this can cause erratic behavior especially on dynamic navmeshes.

Implementation notes on recast-related classes

GatherNavigationDataGeometry seems to pull values out of the nav relevant interface

FRecastTileGenerator::PrepareGeometrySources collects the NavigationRelevantData list which is used to generate the obstacles used in the navmesh. This method is virtual.

It seems the generator has a “parent generator” FRecastNavMeshGenerator which provides some functionality like telling it whether to generate for a given tile

FRecastNavMeshGenerator spawns the FRecastTileGenerator in ConstructTileGeneratorImpl where it passes itself as the parent

ARecastNavMesh creates FRecastNavMeshGenerator in CreateGeneratorInstance which, is overridable

include recast.h error: need Navmesh in build.cs deps, not just NavigationSystem