IsPathPossible returns true, followed by Pathfinding.ABPath error

General Grid graph
1

Hello,

I am trying to check for a path that I know will be blocked by wall, and therefore impassible. I am using something like this:

GraphNode node1 = AstarPath.active.GetNearest(point1, NNConstraint.Default).node;
GraphNode node2 = AstarPath.active.GetNearest(point2, NNConstraint.Default).node;

if (PathUtilities.IsPathPossible(node1, node2)) {
    // Yay, there is a path between those two nodes
}

I tried adding traverseable tags to the nnconstraint, with no luck. I set point 1 to the seeker’s current transform position, and point 2 to the destination object’s position. I also tried NNConstraint.None, but it still keeps returning true.

2

Hi

Is this wall blocked because it has a tag that is not traversable? The IsPathPossible method only checks for if there is a path of walkable nodes between the start and end, it does not check for tags at all.
There is another overload of the IsPathPossible method that takes a tag mask as well, however that is significantly slower as it cannot use precalculated data.

3

This wall has a tag that marks the area it covers as non-traversable, for that particular seeker type. I thought setting the constraint’s tags would solve this, but it didn’t seem to work.

NNConstraint nnConstraint = NNConstraint.Default;
nnConstraint.tags = Seeker.traversableTags;
4

I did see this version of the function:

IsPathPossible (nodes, tagMask)
Returns if there are walkable paths between all nodes.

But that is a check for all nodes, whereas I only need it between 2 points, so that I know which path failed.

5

Hi

You can just make a list of size two then. That will be equivalent.

1 Like
6

Ohhhh, my bad, I thought it did a check to see whether travel is possible between any two node combinations on the entire grid. (facepalm)

It works, thank you!

1 Like