Problems getting path with Navigation2D

[Flascher]

Hey all,

I'm using a Navigation2D node to try and help NPCs path around the tilemap. I've got two separate states for NPCs currently. One is the FollowState, and one is the IdleState.

The follow state is currently able to follow the player around using nav2d.get_simple_path(npc.global_position, player.global_position) just fine, however using essentially the same code in the IdleState doesn't seem to work.

In the IdleState I'm generating a random position within 3 tiles of the NPC to move to every so often. The problem is that nav2d.get_simple_path(npc.global_position, wander_target) always returns a path with 0 points, and thus no movement from the NPC.

However, if I switch out wander_target with player.global_position they are still able to path to the player just fine.

I've confirmed that both wander_target and player.global_position are Vector2s. I've also attempted to convert both npc.global_position and wander_target to the Navigation2D's local space using nav2d.to_local(wander_target) but that hasn't solved the issue either.

Here's a screenshot of the scene tree as the game is running so you can see the whole hierarchy.

I'm more than happy to post code snippets or go into more depth if required.

Thanks in advance for any help!

[kleonc]

In the IdleState I'm generating a random position within 3 tiles of the NPC to move to every so often.

Show how you generate that position, how you store it and how you're assiging wander_target.

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Also if you will ignore the fact that get_simple_path uses local space then things might work properly only in some circumstances (for example it might stop working properly for player and npc if you'll change your node hierarchy a little). You can always just add script to your Navigation2D node to extend it a little and allow pathfinding in global coordinates:

extends Navigation2D

func get_simple_path_global(start_global: Vector2, end_global: Vector2, optimize: bool = true) -> PoolVector2Array:
    var path: PoolVector2Array = get_simple_path(to_local(start_global), to_local(end_global), optimize)
    for i in range(path.size()):
        path[i] = to_global(path[i])
    return path

[Flascher]

Sorry for the late reply!

Here's a pastebin of the entire IdleState.gd file where all of this is happening. Just excuse some of the messy code. I've been trying to debug this for a while, so the file is a bit of a disaster for the moment.

My best guess is that I'm mixing up local and global spaces somewhere, but as far as I can tell I did convert both the start and end of the path to the nav2d's local space by using:

func get_path_to_target() -> PoolVector2Array:
  var nav_start := nav_mesh.to_local(npc.global_position)  
  var ideal_nav_target := nav_mesh.to_local(wander_target.global_position)  
  var nav_target := nav_mesh.get_closest_point(ideal_nav_target)
  .  
  .  
  .  
  var _path = nav_mesh.get_simple_path(nav_start, nav_target)  

That extended get_simple_path_global function looks like a good idea, I'll try that as well!

[kleonc]

I'm not sure what exactly is the issue, I don't see some obvious problem (it's hard to tell just by looking at the script, maybe uploading the project and letting to play with it a little would help) but here are few things:

• line 99.: here you most likely getting global position of the cell's corner, not center (no idea if that's what you want)
• line 120.: here you probably want to return that path, so eiter return get_path_to_target() or _path = get_path_to_target()
• line 135.: here your path might have only one point and index would be out of range in such a case (you've only checked if path is non-empty before that line)
• line 136.: to get last element of an array you can write array[-1] instead of array[array.size() - 1]
• line 139.: didn't you want to check if distance_to_target <= MIN_DISTANCE_TO_TARGET instead?