Create and Destroy NavGraphs at Runtime

LayerGridGraphToggle.cs

using Pathfinding;
using System.Collections;
using UnityEngine;

public class LayerGridGraphToggle : MonoBehaviour {

    public int Width = 200; // (nodes)
    public int Depth = 200; // (nodes)
    public float NodeSize = 0.5f;
    public Vector3 Center = Vector3.zero;

    public KeyCode ToggleKeyCode = KeyCode.Alpha1;
    bool ToggleIsOn = false;

    // An already existing NavGraph with a Width & Depth of One that we can copy settings from
    static LayerGridGraph _ReferenceLayerGridGraph;
    static LayerGridGraph ReferenceLayerGridGraph {
        get {
            if( _ReferenceLayerGridGraph == null && AstarPath.active != null ) {
                _ReferenceLayerGridGraph = AstarPath.active.data.FindGraph(navGraph => {
                    LayerGridGraph layerGridGraph = navGraph as LayerGridGraph;
                    if( layerGridGraph == null )
                        return false;
                    if( layerGridGraph.width > 1 || layerGridGraph.depth > 1 )
                        return false;
                    return true;
                }) as LayerGridGraph;

                // Remove the reference graph
                if( _ReferenceLayerGridGraph != null ) {
                    AstarPath.active.data.RemoveGraph(_ReferenceLayerGridGraph);
                }
            }
            return _ReferenceLayerGridGraph;
        }
    }

    // The Graph for this Toggle
    LayerGridGraph LayerGridGraph = null;


    // Editor Gizmos
    Color OnColor  = new Color(0, 1, 0, 0.25f); // Green
    Color OffColor = new Color(1, 0, 0, 0.25f); // Red
    private void OnDrawGizmos() {
        Gizmos.color = ToggleIsOn ? OnColor : OffColor;
        Gizmos.DrawCube( Center, new Vector3(Width * NodeSize, 1, Depth * NodeSize) );
    }

    private void Start() {
        ToggleOn();
    }

    void Update () {
        if( ReferenceLayerGridGraph == null )
            return;

	if( Input.GetKeyDown(ToggleKeyCode) ) {
            if( ToggleIsOn == false )
                ToggleOn();
            else
                ToggleOff();
        }
    }

    // Create the NavGraph
    void ToggleOn() {
        LayerGridGraph = AstarPath.active.data.AddGraph(typeof(LayerGridGraph)) as LayerGridGraph;
        // Dynamic Settings
        LayerGridGraph.SetDimensions(Width, Depth, NodeSize);
        LayerGridGraph.center = Center;

        // Reference Settings (I don't know a better way to copy them)
        LayerGridGraph.neighbours = ReferenceLayerGridGraph.neighbours;
        LayerGridGraph.characterHeight = ReferenceLayerGridGraph.characterHeight;
        LayerGridGraph.cutCorners = ReferenceLayerGridGraph.cutCorners;
        LayerGridGraph.maxClimb = ReferenceLayerGridGraph.maxClimb;
        LayerGridGraph.maxSlope = ReferenceLayerGridGraph.maxSlope;
        LayerGridGraph.erodeIterations = ReferenceLayerGridGraph.erodeIterations;
        LayerGridGraph.collision.collisionCheck = ReferenceLayerGridGraph.collision.collisionCheck;
        LayerGridGraph.collision.type = ReferenceLayerGridGraph.collision.type;
        LayerGridGraph.collision.diameter = ReferenceLayerGridGraph.collision.diameter;
        LayerGridGraph.collision.height = ReferenceLayerGridGraph.collision.height;
        LayerGridGraph.collision.collisionOffset = ReferenceLayerGridGraph.collision.collisionOffset;
        LayerGridGraph.collision.mask = ReferenceLayerGridGraph.collision.mask;
        LayerGridGraph.collision.heightCheck = ReferenceLayerGridGraph.collision.heightCheck;
        LayerGridGraph.collision.fromHeight = ReferenceLayerGridGraph.collision.fromHeight;
        LayerGridGraph.collision.heightMask = ReferenceLayerGridGraph.collision.heightMask;
        LayerGridGraph.collision.thickRaycast = ReferenceLayerGridGraph.collision.thickRaycast;
        LayerGridGraph.collision.unwalkableWhenNoGround = ReferenceLayerGridGraph.collision.unwalkableWhenNoGround;
        LayerGridGraph.penaltyPosition = ReferenceLayerGridGraph.penaltyPosition;
        LayerGridGraph.penaltyPositionOffset = ReferenceLayerGridGraph.penaltyPositionOffset;
        LayerGridGraph.penaltyPositionFactor = ReferenceLayerGridGraph.penaltyPositionFactor;

        StartCoroutine(ScanAsync(LayerGridGraph));

        ToggleIsOn = true;
    }

    IEnumerator ScanAsync( NavGraph navGraph ) {
        // Only 1 NavGraph can scan at a time
        while( AstarPath.active.isScanning )
            yield return 0;

        // Check if the NavGraph has been removed before the scanning can start
        if( navGraph.active == null )
            yield break;

        foreach( Progress progress in AstarPath.active.ScanAsync(navGraph) )
            yield return 0;
    }

    // Destroy the NavGraph
    void ToggleOff() {
        AstarPath.active.data.RemoveGraph(LayerGridGraph);
        LayerGridGraph = null;

        ToggleIsOn = false;
    }
}