Path following thinks it has reached the destination actor while still outside of acceptance radius

Development Programming & Scripting
, ,
1

Here’s what I noticed when debugging the path following component code:

In UPathFollowingComponent::UpdatePathSegment() there is the following conditional statement

else if (MoveSegmentEndIndex > PreciseAcceptanceRadiusCheckStartNodeIndex && HasReachedDestination(CurrentLocation))In the case I mentioned above the MoveSegmentEndIndex is 1 and the PreciseAcceptanceRadiusCheckStartNodeIndex is 0 so we also check HasReachedDestination(CurrentLocation).

Within that function, GoalLocation is set as follows

FVector GoalLocation = *Path->GetPathPointLocation(Path->GetPathPoints().Num() - 1);but there was a recent change to the engine code which then sets GoalLocation equal to the CurrentDestination which is the end of the current segment. The current segment will not be equal to the location of the goal actor if we’re not on the last segment of the path yet. So HasReachedDestination(CurrentLocation) will return true if the character is within the acceptance radius of the end of the current segment instead, not within the acceptance radius of the goal actor.

Maybe I’m misunderstanding the goal of these recent changes but this logic seems incorrect to me.

2

Steps to Reproduce

  1. Place a character with a path following component on navmesh very close to a goal actor.
  2. Configure the navmesh so the pathfinding returns a path with 3 path points (2 segments). I used an acceptance radius of 67.5.
  3. Use a MoveTo task to get the character to move to the goal actor.
  4. Observe that the path following will report that is has finished following the path before reaching the acceptance radius of the goal actor.
3

That is odd behavior. Would you be able to share more of your setup that reproduces this issue? I have been attempting to repro it, but so far I have not seen the issue in my testing. Are you using the default pathfollowing or crowd following?

As for why the change was made, it came from Lego FN to test reachability of the actor prior to setting the goal as the actor’s location. I do not see any changes in the function since this change was introduced on our latest in UE5 Main.

-James

4

I am also running into a similar issue with the same line of code. In my case, I have a simple path from X = -330 to X = +330, with 3 path points (start, (0,0,7.5), end).

My acceptance radius is large at 400, which is to cause the pathing to stop when in range of a ranged attack. The character is supposed to path from their start until they are in range, then attack.

However, HasReachedDestination() returns true, because as part of pathing along that path, it checks against CurrentDestination, which at the start is set to the middle point near the origin. Since they are within 400 units of that, the path completes early without being in the proper range of the destination.

CurrentDestination checking, from what I can tell, is supposed to be (and is properly) checked in HasReachedCurrentTarget(), so I am not sure why it is used in this case.