How to test if a position is in Navmesh?

Development Programming & Scripting C++
1

I searched on forum and it says that UNavigationSystem::ProjectPointToNavigation() is the function to check if a position is in NavMesh, but when put a Cube that Scale is 20.f at location(2000.f, 2000.f) on my Level, and use test code:


UNavigationSystem* const NavSys = GetWorld()->GetNavigationSystem();
FNavLocation Loc1;
FNavLocation Loc2;
FNavLocation Loc3;
FNavLocation Loc4;
FNavLocation Loc5;
FNavLocation Loc6;

bool rs1 = NavSys->ProjectPointToNavigation(FVector(2000.f, 2000.f, 0.f), Loc1);
bool rs2 = NavSys->ProjectPointToNavigation(FVector(1500.f, 1500.f, 0.f), Loc2);
bool rs3 = NavSys->ProjectPointToNavigation(FVector(1000.f, 1000.f, 0.f), Loc3);
bool rs4 = NavSys->ProjectPointToNavigation(FVector(900.f, 900.f, 0.f), Loc4);
bool rs5 = NavSys->ProjectPointToNavigation(FVector(800.f, 800.f, 0.f), Loc5);
bool rs6 = NavSys->ProjectPointToNavigation(FVector(500.f, 500.f, 0.f), Loc6);

all return value are true, Is there any wrong to use ProjectPointToNavigation? or how to use ProjectPointToNavigation?

2

Have anyone comes across this problem?

3

ProjectPointToNavigation doesn’t check if the position is on navmesh. It returns the closest position that is on the navmesh instead.
See this:
https://docs.unrealengine.com/latest/INT/API/Runtime/Engine/AI/Navigation/UNavigationSystem/ProjectPointToNavigation/1/index.html
It returns FVector, not bool.

4

Yep, you’re right. I have sorted it out with UNavigationSystem::TestPathSync :


UNavigationSystem* const NavSys = GetWorld()->GetNavigationSystem();
APlayerController* PC = GetWorld()->GetFirstPlayerController();
if (!NavSys || !PC)
{
	return;
}

const ANavigationData* NavData = NavSys->GetNavDataForProps(PC->GetNavAgentPropertiesRef());
if (!NavData)
{
	return;
}

FVector TestLoc(1000.f, 1000.f, 0.f);
FPathFindingQuery Query(PC, *NavData, PC->GetNavAgentLocation(), TestLoc);
if (!NavSys->TestPathSync(Query))
{
	return;
}