I worked a lot on the NPC Anua who is the main character's niece in Planet of Lana II. Anua is based on Muis behaviours and edited to follow scripted commands placed in the world. Anua can navigate through tunnels and follow around the environment that Lana moves through, she has a couple of different behaviours: Stay, follow, waypoint & Hide.

These commands are abstract classes that correspond to behaviours with custom data that the designers have set in the scene.

In this class there are two virtual variables that can be overridden to customize the behaviour of when the commands are added.

MustBeLastCommand will remove itself from the list instantly when a new command has been added to the list. I use this on the Hide,Stay and Follow command since their condition for being finished depends on receiving new instructions.

CancelOtherCommands bool will remove all previous commands in the list before adding the new command, this variable is used by the designer in the trigger if they want to stay or hide instantly.

Abstract command class

public override AbstractCommand GetNewCommand()
{
    if (commandList.Count < 1)
    {
        Debug.LogWarning($"No Command has been given yet! Defaulting to stay behaviour @ {this}");

        SetCurrentCommand(new AnuaStayCommand());

        return currentCommand;
    }

    SetCurrentCommand(commandList[0]);
    commandList.RemoveAt(0);

    return currentCommand;
}

#region Commands

[Serializable]
public class AnuaWaypointCommand : AbstractCommand
{
    [ReadOnly] public String CommandName = "Waypoint Command";

    public override CommandType Type => CommandType.Waypoint;

    public AnuaWaypointCommand(Vector3 waypoint) { wayPointPos = waypoint; relativeToTransform = null; }
    public AnuaWaypointCommand(Vector3 waypointOffset, Transform waypointTransform) { offset = waypointOffset; relativeToTransform = waypointTransform; }

    public Vector3 WayPointTarget => relativeToTransform != null ? relativeToTransform.position + offset : wayPointPos + offset;

    public Transform relativeToTransform;
    public Vector3 wayPointPos;
    public Vector3 offset;
}

In Unity there are triggers and callbacks placed by game designers to steer her behaviour where they can cancel previous commands or add a list of commands that she should execute in a set order. For this I made a custom editor to create the commands in the command list.

There are also custom paths where Anua goes off the navmesh,these are for example the pipes she crawls through in the first chapter. We use these paths for transitions between puzzles and areas. These paths can either be forced by the Custompath command or be used as a navlink when Anua is waypointing.

The custom paths can have custom data attached to the nodes, I use these to configure Anua's behaviour when performing the path to play her crawl animation to exit/enter the tunnel. I also use this to teleport her from one node to another.

Custom editor creating custom commands.

if (GUILayout.Button("Create Command"))
{
    AnuaCommands.AbstractCommand newCommand = null;

    switch (triggerCommandAnua.commandType)
    {
        case AnuaCommands.CommandType.Stay:
            newCommand = new AnuaCommands.AnuaStayCommand();
            break;
        case AnuaCommands.CommandType.Follow:
            newCommand = new AnuaCommands.AnuaFollowCommand();

            break;
        case AnuaCommands.CommandType.Waypoint:
            newCommand = new AnuaCommands.AnuaWaypointCommand(triggerCommandAnua.gameObject.transform.position);

            break;
        case AnuaCommands.CommandType.CustomPath:
            newCommand = new AnuaCommands.AnuaCustomPathCommand(null);

            break;
        case AnuaCommands.CommandType.Hide:
            newCommand = new AnuaCommands.AnuaHideCommand();

            break;
    }

    triggerCommandAnua.commandList.Add(newCommand);
    EditorUtility.SetDirty(triggerCommandAnua);
}

Here is a video in the first chapter where Anua is waypointing through the environment to follow Lana.

You can see Anua using a custom path in the pipe and teleporting to the hole to prevent the player from waiting on Anua to crawl through the whole pipe.

Anua showcase

MOLLY TANDBERG

Planet of lana 2 - Anua