doprez / doprez.stride.ai

a Library meant to be used to handle AI in Stride games

Doprez.Stride

AI libraries to be used within Stride3d games

Build Status

Examples

FSM Example

We can start by inheriting from the FSM and implementing the base methods

using Doprez.Stride.AI.FSMs;

public class BasicEnemyFSM : FSM
{
	public override void UpdateFSM()
	{
		//You can add triggers here to cancel/change the current running state
	}
}

Create the State and needed methods

public class IdleState : FSMState
{
	public IdleState(FSM fsm)
	{
		// set the FSM to access the methods within the running state
		FiniteStateMachine = fsm;

		// add this state to the FSM for other states to see this state
		FiniteStateMachine.States.Add(0, this);
	}

	public override void EnterState()
	{
		// activate needed events or variables when this state is started
	}

	public override void ExitState()
	{
		// deactivate needed events or variables when this state is finished
	}

	public override void UpdateState()
	{
		// this runs in the Update method of Stride per frame
	}

}

A more complete example

you can add the Doprez.Stride nuget package if some of the references are missing

the FSM to initialize the state and allow per frame updates

using System;
using Doprez.Stride.AI.FSMs;
using Stride.Core;
using Stride.Engine;
using StridePlatformer.States;
using Navigation;

public class BasicEnemyFSM : FSM
{
	[Display("Player Entity")]
	[DataMember(0)]
	public Entity Player{get;set;}

	[Display("Player Seen Trigger")]
	[DataMember(2)]
	public PhysicsComponent PlayerSeenTrigger;

	[Display("Animation Component")]
	[DataMember(20)]
	public AnimationComponent AnimationComponent { get; set; }

	//States
	//private MoveToState _moveTo;
	private IdleState _idle;


	public override void Start()
	{
		InitializeStates();

		SetCurrentState(_idle);
	}

	private void InitializeStates()
	{
		_idle = new IdleState(this, AnimationComponent);// ", _moveTo" add this if you added a moveTo state
		_idle.PlayerSeenTrigger = PlayerSeenTrigger;
	}

	public override void UpdateFSM()
	{
		// add some logic here if needed but it can just be blank
	}
}

An example Idle state with comments on how to change to another state

using System.Collections.Specialized;
using System.Threading.Tasks;
using Doprez.Stride.AI.FSMs;
using Stride.Core.Collections;
using Stride.Engine;
using Stride.Physics;

public class IdleState : FSMState
{

	public PhysicsComponent PlayerSeenTrigger;

	private readonly AnimationComponent _animationComponent;
	//add a state for you to change to like the example below
	//private readonly MoveToState _moveTo;

	public IdleState(FSM fsm, AnimationComponent animationComponent)// , MoveToState moveTo
	{
		FiniteStateMachine = fsm;
		_animationComponent = animationComponent;
		//_moveTo = moveTo;

		FiniteStateMachine.States.Add((int)EnemyStates.Idle, this);
	}

	public override void EnterState()
	{
		//Only activate this trigger while the state is running
		PlayerSeenTrigger.Enabled = true;
		PlayerSeenTrigger.Collisions.CollectionChanged += CollisionsChanged;

		//run the idle anim if you have one
		//_animationComponent.Play("Idle");
	}

	public override void ExitState()
	{
		// stop using the trigger when the state isnt running
		PlayerSeenTrigger.Enabled = false;
		PlayerSeenTrigger.Collisions.CollectionChanged -= CollisionsChanged;
	}

	public override void UpdateState()
	{
		
	}

	private void CollisionsChanged(object sender, TrackingCollectionChangedEventArgs args)
	{
		// Cast the argument 'Item' to a collision object
		var collision = (Collision)args.Item;

		// We need to make sure which collision object is not the Trigger collider
		// We perform a little check to find the ballCollider 
		var playerCollider = PlayerSeenTrigger == collision.ColliderA ? collision.ColliderB : collision.ColliderA;

		if (args.Action == NotifyCollectionChangedAction.Add)
		{
			// When a collision has been added to the collision collection, we know an object has 'entered' our trigger
			if (playerCollider.Entity.Name == "PlayerCharacter")
			{
				//get the entity that entered the trigger
				var entitycollided = playerCollider.Entity;
				//you can change the state by direct reference or the dictionary Id
				//_moveTo.Target = entitycollided;
				// change to a direct reference
				//FiniteStateMachine.SetCurrentState(_moveTo);
				// change based on a dictionary reference I would recommend setting up and Enum for readability
				//FiniteStateMachine.SetCurrentState(1);
			}
		}
	}
	
}

GOAP example

TBD