How can I improve my A* pathfinding function to consider tags and penalties

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  • A* version: 5.0.6
  • Unity version: 2022.3.49f1

I’m working on a custom pathfinding function in Unity using the A* Pathfinding Project. My current implementation calculates a path between a start and end position, but it’s not considering tags or penalties as intended. It’s does calculate the path. Here’s my current code:

public void CalculatePath(Vector3 start, Vector3 dest, OnPathDelegate onPathCompleteDistance, AIGraphMask aIGraphMask, bool blockUntilCalculated = false, bool pushToFront = false)
{
    NNInfo nearestNodeInfo = AstarPath.active.GetNearest(dest);

    // Check if the node is walkable
    if (nearestNodeInfo.node != null && nearestNodeInfo.node.Walkable)
    {
        var path = ABPath.Construct(start, dest, onPathCompleteDistance);

        // Set the graph mask if specified
        path.nnConstraint.graphMask = AStarPathfinding.GetGraphMask(aIGraphMask);
        path.nnConstraint.tags = (1 << 0);

        path.nnConstraint.constrainWalkability = true;
        path.nnConstraint.constrainArea = true;
        path.nnConstraint.constrainTags = true;
        path.nnConstraint.constrainDistance = true;

        AstarPath.StartPath(path, pushToFront);

        if (blockUntilCalculated)
        {
            path.BlockUntilCalculated();
        }
    }
}

I have a few specific questions:

  1. Why isn’t my function considering tags even though I’ve set path.nnConstraint.tags = (1 << 0) and path.nnConstraint.constrainTags = true?
  2. How can I modify this function to take penalties into account when calculating the path?
  3. Are there any other improvements or best practices I should consider for this pathfinding implementation?

Any help or guidance would be greatly appreciated. Thanks!

2

Hi

For historical reasons, the nearest node constraint and the path settings are distinct.
You can set:

path.enabledTags = ...;
path.tagPenalties = ...;
3

Thank you for the previous help. I’ve managed to get the tags working correctly in my pathfinding function, but I’m still having issues with penalties. Here’s my current situation:

  1. I’m setting penalties for specific nodes using this code:

csharp

var pathNode = AstarPath.active.GetNearest(node.worldPosition, nn).node;
pathNode.Penalty = 6000;
  1. I’m not using tagPenalties, but rather setting penalties directly on nodes.
  2. When I calculate the path, I want it to consider these node-specific penalties that I’ve set.
4

Hi

It should consider these penalties by default.