Struct NearestNodeConstraint

bool allNodesAreSuitable

True if all nodes are suitable with respect to the constraints set in this struct.

The Suitable method will return true for all nodes if this is true.

int area

Area ID to constrain to.

Will not affect anything if negative.

DistanceMetric distanceMetric

Determines how to measure distances to the navmesh.

The default is a euclidean distance, which works well for most things.

System.Func<GraphNode, bool> filter

Allow only nodes which the given filter function returns true for.

The other constraints on this struct will still apply, in addition to the filter function.

var nearestNodeConstraint = NearestNodeConstraint.None;

// Set a custom filter. This can be an arbitrary function which takes a GraphNode and returns true or false.
nearestNodeConstraint.filter = (GraphNode node) => ((Vector3)node.position).y > 50;

// Find the closest node to our position which is above y=50
var nearest = AstarPath.active.GetNearest(transform.position, nearestNodeConstraint);


GraphMask graphMask

Graphs which are traversable.

This is a bitmask, meaning that bit 0 specifies whether or not the first graph in the graphs list should be included in the search, bit 1 specifies whether or not the second graph should be included, and so on.

var traversalConstraint = TraversalConstraint.None;

// Allows the first and fourth graphs to be searched, but not the rest
traversalConstraint.graphMask = GraphMask.FromGraphIndex(0) | GraphMask.FromGraphIndex(3);

// Allows the two named graphs to be searched, but not the rest
traversalConstraint.graphMask = GraphMask.FromGraphName("My Custom Graph Name") | GraphMask.FromGraphName("My Other Graph");


float??? maxDistance

The maximum distance to the navmesh to search before the search fails.

This is the maximum distance from the query point to the closest point on the navmesh. If null (the default), the default limit set on the AstarPath component will be used ( AstarPath.maxNearestNodeDistance).

Positive infinity is a valid value, meaning it will search for the closest node regardless of distance. 0 is also a valid value, but it usually only makes sense with a different distance metric than the default.

float maxDistanceSqr

Squared maxDistance.

Negative value means to use the default A* limit ( AstarPath.maxNearestNodeDistance). Positive value means to use a custom limit.

Typically you'll modify maxDistance instead of this.

int tags

Set of tags which are traversable.

This is a bitmask, i.e bit 0 indicates that tag 0 is traversable, bit 3 indicates tag 3 is traversable etc.

By default all tags are traversable, which corresponds to the value -1.

var traversalConstraint = TraversalConstraint.None;

// Allows the first and third tags to be searched, but not the rest
traversalConstraint.tags = (1 << 0) | (1 << 2);

// Allows the two named tags to be searched, but not the rest
traversalConstraint.tags = PathfindingTag.FromName("Grass").ToMask() | PathfindingTag.FromName("Lava").ToMask();
If you are using the Seeker or FollowerEntity components, you can access this in the inspector via the tags foldout:

ITraversalProvider traversalProvider

Allow traversing only nodes that are also traversable by the given ITraversalProvider.

The other constraints on this struct will still apply, in addition to the ITraversalProvider.

WalkabilityConstraint walkable

Constraint to only search only walkable nodes, only unwalkable nodes, or both.

NearestNodeConstraint None = new NearestNodeConstraint { traversal = TraversalConstraint.None, distanceMetric = DistanceMetric.Euclidean, area = -1, maxDistanceSqr = -1, walkable = WalkabilityConstraint.DontCare, }

Constraint which allows all nodes.

NearestNodeConstraint Walkable = new NearestNodeConstraint { traversal = TraversalConstraint.None, distanceMetric = DistanceMetric.Euclidean, area = -1, maxDistanceSqr = -1, walkable = WalkabilityConstraint.Walkable, }

Constraint which filters out all unwalkable nodes.

WalkabilityConstraint

TraversalConstraint traversal

Sub-filter with more constraints.