Class LayerGridGraph Extends GridGraph, IUpdatableGraph

int LayerCount

Number of layers in the graph.

For grid graphs this is always 1, for layered grid graphs it can be higher. The nodes array has the size width*depth*layerCount.

int MaxLayers

float characterHeight = 0.4F

Nodes with a short distance to the node above it will be set unwalkable.

int Depth

const int FixedPrecisionScale = 1024

Scaling used for the coordinates in the Linecast methods that take normalized points using integer coordinates.

To convert from world space, each coordinate is multiplied by this factor and then rounded to the nearest integer.

Typically you do not need to use this constant yourself, instead use the Linecast overloads that do not take integer coordinates.

int LayerCount

Number of layers in the graph.

For grid graphs this is always 1, for layered grid graphs it can be higher. The nodes array has the size width*depth*layerCount.

int MaxLayers

RecalculationMode

float StandardDimetricAngle = Mathf.Acos(1/2f)*Mathf.Rad2Deg

Commonly used value for isometricAngle.

float StandardIsometricAngle = 90-Mathf.Atan(1/Mathf.Sqrt(2))*Mathf.Rad2Deg

Commonly used value for isometricAngle.

int Width

AstarPath active

Reference to the AstarPath object in the scene.

float aspectRatio = 1F

Scaling of the graph along the X axis.

This should be used if you want different scales on the X and Y axis of the grid

This option is only visible in the inspector if the graph shape is set to isometric or advanced.

Bounds bounds

World bounding box for the graph.

This always contains the whole graph.

Bounds bounds

World bounding box for the graph.

This always contains the whole graph.

It is ok for a graph type to return an infinitely large bounding box, but this may make some operations less efficient. The point graph will always return an infinitely large bounding box.

Vector3 center

Center point of the grid in world space.

The graph can be positioned anywhere in the world.

GraphCollision collision = new GraphCollision()

Settings on how to check for walkability and height.

bool cutCorners = true

If disabled, will not cut corners on obstacles.

If this is true, and neighbours is set to Eight, obstacle corners are allowed to be cut by a connection.

int depth

Depth (height) of the grid in nodes.

Grid graphs are typically anywhere from 10-500 nodes wide. But it can go up to 1024 nodes wide by default. Consider using a recast graph instead, if you find yourself needing a very high resolution grid.

This value will be clamped to at most 1024 unless ASTAR_LARGER_GRIDS has been enabled in the A* Inspector -> Optimizations tab.

bool drawGizmos = true

Enable to draw gizmos in the Unity scene view.

In the inspector this value corresponds to the state of the 'eye' icon in the top left corner of every graph inspector.

int erodeIterations

Number of times to erode the graph.

The graph can be eroded to add extra margin to obstacles. It is very convenient if your graph contains ledges, and where the walkable nodes without erosion are too close to the edge.

Below is an image showing a graph with 0, 1 and 2 erosion iterations:

int erosionFirstTag = 1

Tag to start from when using tags for erosion.

int erosionTagsPrecedenceMask = -1

Bitmask for which tags can be overwritten by erosion tags.

When erosionUseTags is enabled, nodes near unwalkable nodes will be marked with tags. However, if these nodes already have tags, you may want the custom tag to take precedence. This mask controls which tags are allowed to be replaced by the new erosion tags.

In the image below, erosion has applied tags which have overwritten both the base tag (tag 0) and the custom tag set on the nodes (shown in red).

In the image below, erosion has applied tags, but it was not allowed to overwrite the custom tag set on the nodes (shown in red).

bool erosionUseTags

Use tags instead of walkability for erosion.

Tags will be used for erosion instead of marking nodes as unwalkable. The nodes will be marked with tags in an increasing order starting with the tag erosionFirstTag. Debug with the Tags mode to see the effect. With this enabled you can in effect set how close different AIs are allowed to get to walls using the Valid Tags field on the Seeker component.

uint graphIndex

Index of the graph, used for identification purposes.

Guid guid

Used as an ID of the graph, considered to be unique.

bool infoScreenOpen

Used in the editor to check if the info screen is open.

Should be inside UNITY_EDITOR only #ifs but just in case anyone tries to serialize a NavGraph instance using Unity, I have left it like this as it would otherwise cause a crash when building. Version 3.0.8.1 was released because of this bug only

uint initialPenalty

Default penalty to apply to all nodes.

InspectorGridMode inspectorGridMode = InspectorGridMode.Grid

Determines the layout of the grid graph inspector in the Unity Editor.

A grid graph can be set up as a normal grid, isometric grid or hexagonal grid. Each of these modes use a slightly different inspector layout. When changing the shape in the inspector, it will automatically set other relevant fields to appropriate values. For example, when setting the shape to hexagonal it will automatically set the neighbours field to Six.

This field is only used in the editor, it has no effect on the rest of the game whatsoever.

If you want to change the grid shape like in the inspector you can use the SetGridShape method.

InspectorGridHexagonNodeSize inspectorHexagonSizeMode = InspectorGridHexagonNodeSize.Width

Determines how the size of each hexagon is set in the inspector.

For hexagons the normal nodeSize field doesn't really correspond to anything specific on the hexagon's geometry, so this enum is used to give the user the opportunity to adjust more concrete dimensions of the hexagons without having to pull out a calculator to calculate all the square roots and complicated conversion factors.

This field is only used in the graph inspector, the nodeSize field will always use the same internal units. If you want to set the node size through code then you can use ConvertHexagonSizeToNodeSize.

bool? is2D

Get or set if the graph should be in 2D mode.

bool isScanned

True if the graph has been scanned and contains nodes.

Graphs are typically scanned when the game starts, but they can also be scanned manually.

If a graph has not been scanned, it does not contain any nodes and it not possible to use it for pathfinding.

float isometricAngle

Angle in degrees to use for the isometric projection.

If you are making a 2D isometric game, you may want to use this parameter to adjust the layout of the graph to match your game. This will essentially scale the graph along one of its diagonals to produce something like this:

A perspective view of an isometric graph.

A top down view of an isometric graph. Note that the graph is entirely 2D, there is no perspective in this image.

For commonly used values see StandardIsometricAngle and StandardDimetricAngle.

Usually the angle that you want to use is either 30 degrees (alternatively 90-30 = 60 degrees) or atan(1/sqrt(2)) which is approximately 35.264 degrees (alternatively 90 - 35.264 = 54.736 degrees). You might also want to rotate the graph plus or minus 45 degrees around the Y axis to get the oritientation required for your game.

You can read more about it on the wikipedia page linked below.

This option is only visible in the inspector if the graph shape is set to isometric or advanced.

float maxSlope = 90

The max slope in degrees for a node to be walkable.

float maxStepHeight = 0.4F

The max y coordinate difference between two nodes to enable a connection.

Set to 0 to ignore the value.

This affects for example how the graph is generated around ledges and stairs.

bool maxStepUsesSlope = true

Take the slope into account for maxStepHeight.

When this is enabled the normals of the terrain will be used to make more accurate estimates of how large the steps are between adjacent nodes.

When this is disabled then calculated step between two nodes is their y coordinate difference. This may be inaccurate, especially at the start of steep slopes.

In the image below you can see an example of what happens near a ramp. In the topmost image the ramp is not connected with the rest of the graph which is obviously not what we want. In the middle image an attempt has been made to raise the max step height while keeping maxStepUsesSlope disabled. However this causes too many connections to be added. The agent should not be able to go up the ramp from the side. Finally in the bottommost image the maxStepHeight has been restored to the original value but maxStepUsesSlope has been enabled. This configuration handles the ramp in a much smarter way. Note that all the values in the image are just example values, they may be different for your scene.

string name

Name of the graph.

Can be set in the unity editor

uint[] neighbourCosts = new uint[8]

Costs to neighbour nodes.

See neighbourOffsets.

int[] neighbourOffsets = new int[8]

Index offset to get neighbour nodes.

Added to a node's index to get a neighbour node index.

Z
|
|

6 2 5
\ | /
-- 3 - X - 1 ----- X
/ | \
7 0 4

|
|


int[] neighbourXOffsets = { 0, 1, 0, -1, 1, 1, -1, -1 }

Offsets in the X direction for neighbour nodes.

Only 1, 0 or -1

int[] neighbourZOffsets = { -1, 0, 1, 0, -1, 1, 1, -1 }

Offsets in the Z direction for neighbour nodes.

Only 1, 0 or -1

NumNeighbours neighbours = NumNeighbours.Eight

Number of neighbours for each node.

Either four, six, eight connections per node.

Six connections is primarily for hexagonal graphs.

float nodeSize = 1

Size of one node in world units.

For a grid layout, this is the length of the sides of the grid squares.

For a hexagonal layout, this value does not correspond to any specific dimension of the hexagon. Instead you can convert it to a dimension on a hexagon using ConvertNodeSizeToHexagonSize.

GridNodeBase[] nodes

All nodes in this graph.

Nodes are laid out row by row.

The first node has grid coordinates X=0, Z=0, the second one X=1, Z=0
the last one has grid coordinates X=width-1, Z=depth-1.

var gg = AstarPath.active.data.gridGraph;
int x = 5;
int z = 8;
GridNodeBase node = gg.nodes[z*gg.width + x];


bool open

Is the graph open in the editor.

bool persistent

True if the graph will be included when serializing graph data.

If false, the graph will be ignored when saving graph data.

Most graphs are persistent, but the LinkGraph is not persistent because links are always re-created from components at runtime.

Vector3 rotation

Rotation of the grid in degrees.

The nodes are laid out along the X and Z axes of the rotation.

For a 2D game, the rotation will typically be set to (-90, 270, 90). If the graph is aligned with the XY plane, the inspector will automatically switch to 2D mode.

GridGraphRules rules = new GridGraphRules()

Additional rules to use when scanning the grid graph.

// Get the first grid graph in the scene
var gridGraph = AstarPath.active.data.gridGraph;

gridGraph.rules.AddRule(new Pathfinding.Graphs.Grid.Rules.RuleAnglePenalty {
penaltyScale = 10000,
curve = AnimationCurve.Linear(0, 0, 90, 1),
});


bool showInInspector

True if the graph should be visible in the editor.

False is used for some internal graph types that users don't have to worry about.

bool showMeshOutline = true

Show an outline of the grid nodes in the Unity Editor.

bool showMeshSurface = true

Show the surface of the graph.

Each node will be drawn as a square (unless e.g hexagon graph mode has been enabled).

bool showNodeConnections

Show the connections between the grid nodes in the Unity Editor.

Vector2 size

Size of the grid.

Will always be positive and larger than nodeSize.

GraphTransform transform = new GraphTransform(Matrix4x4.identity)

Determines how the graph transforms graph space to world space.

Vector2 unclampedSize = new Vector2(10, 10)

Size of the grid.

Can be negative or smaller than nodeSize

bool uniformEdgeCosts

If true, all edge costs will be set to the same value.

If false, diagonals will cost more. This is useful for a hexagon graph where the diagonals are actually the same length as the normal edges (since the graph has been skewed)

If the graph is set to hexagonal in the inspector, this will be automatically set to true.

int width

Width of the grid in nodes.

Grid graphs are typically anywhere from 10-500 nodes wide. But it can go up to 1024 nodes wide by default. Consider using a recast graph instead, if you find yourself needing a very high resolution grid.

This value will be clamped to at most 1024 unless ASTAR_LARGER_GRIDS has been enabled in the A* Inspector -> Optimizations tab.

const int HexagonConnectionMask = 0b010101111

Mask based on hexagonNeighbourIndices.

This indicates which connections (out of the 8 standard ones) should be enabled for hexagonal graphs.

int hexagonConnectionMask = 0;
for (int i = 0; i < GridGraph.hexagonNeighbourIndices.Length; i++) hexagonConnectionMask |= 1 << GridGraph.hexagonNeighbourIndices[i];


int[] allNeighbourIndices = { 0, 1, 2, 3, 4, 5, 6, 7 }

Which neighbours are going to be used when neighbours=8.

int[] axisAlignedNeighbourIndices = { 0, 1, 2, 3 }

Which neighbours are going to be used when neighbours=4.

bool exists

True if the graph exists, false if it has been destroyed.

int[] hexagonNeighbourIndices = { 0, 1, 5, 2, 3, 7 }

Which neighbours are going to be used when neighbours=6.

int lastScannedDepth

int lastScannedWidth

int layerCount

Number of layers.

System.Func<GridNodeBase> newGridNodeDelegate = () => new GridNode()

Delegate which creates and returns a single instance of the node type for this graph.

This may be set in the constructor for graphs inheriting from the GridGraph to change the node type of the graph.

GridGraphNodeData nodeData

Internal data for each node.

It also contains some data not stored in the node objects, such as normals for the surface of the graph. These normals need to be saved when the maxStepUsesSlope option is enabled for graph updates to work.

refGridGraphNodeData nodeDataRef

bool useRaycastNormal

Use heigh raycasting normal for max slope calculation.

True if maxSlope is less than 90 degrees.