Struggling with A* Pathfinding Algorithm in Unity - Inconsistent Pathfinding Results
I'm a bit lost with I tried several approaches but none seem to work. I'm implementing the A* pathfinding algorithm in Unity (version 2021.3.0f1) for a grid-based game, but I'm encountering inconsistent pathfinding results. Specifically, when the start and end points are the same, I expect the path to return immediately without any additional calculations. However, I'm noticing that my code still goes through the entire process of adding nodes to the open list, which seems unnecessary. I've set up my grid with nodes represented as a 2D array, and each node has a gCost, hCost, and fCost for the A* algorithm. Here’s a simplified version of my node class and the A* implementation: ```csharp public class Node { public Vector3 Position; public float gCost; public float hCost; public float fCost => gCost + hCost; public Node Parent; } public List<Node> FindPath(Vector3 start, Vector3 target) { Node startNode = new Node { Position = start }; Node targetNode = new Node { Position = target }; if (startNode.Position == targetNode.Position) { return new List<Node> { startNode }; } List<Node> openList = new List<Node>(); HashSet<Node> closedList = new HashSet<Node>(); openList.Add(startNode); while (openList.Count > 0) { Node currentNode = openList[0]; for (int i = 1; i < openList.Count; i++) { if (openList[i].fCost < currentNode.fCost || (openList[i].fCost == currentNode.fCost && openList[i].hCost < currentNode.hCost)) { currentNode = openList[i]; } } openList.Remove(currentNode); closedList.Add(currentNode); // Check neighbors and update costs... } return null; // Path not found } ``` When I run this with the start and target being the same, I still see multiple nodes being processed, which is not what I expect. I've also verified that my equality check (using `==`) for the Vector3 positions works correctly, but it seems like the code still treats it as if it were different nodes. I’ve tried using `Vector3.Equals()` and `Vector3.Distance()` to check the proximity, but that hasn't improved the situation. Additionally, I have debug logs showing the node processing, and it's clear that it doesn't recognize the start as the end, leading to unnecessary calculations. Is there a more efficient way to handle this scenario in the A* algorithm implementation? What am I missing here to ensure that the pathfinding process exits early when the start and end points are the same? How would you solve this?