NULL reference exception when applying penalty

General
#1

Hi, I am making a RTS and I tried this so that the path generated avoids units. However, my units aren’t moving at all.

I called OnStop() in the Awake(). Whenever I set a new destination, I call OnMove() and then set CanMove to true. If I dont call OnStop() nor OnMove() my units move.

Could you help me with this problem? Not sure why it ain’t working.

if (hit.transform.tag == "Terrain") { mover.objetivo = targetPoint; mover.OnMove(); mover.canMove=true; }

Here are the functions posted in the link:

` public void OnStop() {
node = AstarPath.active.GetNearest(transform.position).node;
Bounds bounds = new Bounds (new Vector3(node.position.x,node.position.y,node.position.z), new Vector3 (0.1f, 0.1f, 0.1f));
guo = new GraphUpdateObject(bounds);
guo.addPenalty = Penalty;
guo.requiresFloodFill = false;
guo.resetPenaltyOnPhysics = false;
guo.updatePhysics = false;
AstarPath.active.UpdateGraphs(guo);
}

public void OnMove() {
	if (node.Penalty >= Penalty) {
		Bounds bounds = new Bounds(new Vector3(node.position.x,node.position.y,node.position.z),new Vector3(0.1f,0.1f,0.1f));
		guo = new GraphUpdateObject(bounds);
		guo.addPenalty = -Penalty;
		guo.requiresFloodFill = false;
		guo.resetPenaltyOnPhysics = false;
		guo.updatePhysics = false;
		AstarPath.active.UpdateGraphs(guo);
	} else {
		Debug.LogWarning("Invalid node penalty " + node.Penalty);
	}
}`

I’m getting NULLReference exceptions in:

node = AstarPath.active.GetNearest(transform.position).node;

and

if (node.Penalty >= Penalty)
Thanks in advance

#2

Well the node variable obviously isn’t set to anything when OnMove is called. So the OnMove function is probably being called before OnStop in some cases.

#3

It seems the OnStop() function isn’t updating the Penalty.

public void OnStop () { Debug.Log ("OnStop()"); node = AstarPath.active.GetNearest (transform.position).node; Bounds bounds = new Bounds (new Vector3 (node.position.x, node.position.y, node.position.z), new Vector3 (4f, 4f, 4f)); guo = new GraphUpdateObject (bounds); guo.addPenalty = Penalty; guo.requiresFloodFill = false; guo.resetPenaltyOnPhysics = false; guo.updatePhysics = false; AstarPath.active.UpdateGraphs (guo); Debug.Log ("Node Penalty: " + AstarPath.active.GetNearest (transform.position).node.Penalty); }

I am getting “Node Penalty: 0”.

I am also using that Debug in the update function and the Node Penalty is always 0. It is never update.

#4

Hi

Graph updates are not applied immediately because pathfinding might be running at the same time. If you want to force graph updates to run, you must use
AstarPath.active.FlushGraphUpdates ();

See: http://arongranberg.com/astar/docs/class_astar_path.php#a1af9d7159ad315612d643fec03afa5bb

Also. node.position is not a Vector3, it is an Int3, you need to cast it to a Vector3 to use it like a world position.
Vector3 nodePosition = (Vector3)node.position;

If you just want to add penalty to a single node, you can however just do
GraphNode node = ... node.Penalty += 10000;

#5

Thanks a lot :heart:
You have been a great help. Now my units dodge other stationary units. I am calling
AstarPath.active.FlushGraphUpdates (); every 1000 updates. It is working as I wanted but as It says in the documentation, the fps drop from 60 to 30 or less for one or two seconds when many agents stop.

Thanks a lot really, you saved me a lot of time.