How to rotate the navmesh agent before start moving?

Unity Engine
,
1

Hello everyone!

I want to rotate the front side of my navmesh agent to the path before starting a movement. I stuck on the calculation of angle between transform.forward and _navMeshAgent.steeringTarget.

This is my code:

using UnityEngine;
using UnityEngine.AI;
using System.Collections;

[DisallowMultipleComponent]
[RequireComponent(typeof(Animator))]
[RequireComponent(typeof(Rigidbody))]
[RequireComponent(typeof(NavMeshAgent))]
[RequireComponent(typeof(CapsuleCollider))]
public class AnimationController : MonoBehaviour
{
    private Animator _animator;
    private Rigidbody _rigidbody;
    private NavMeshAgent _agent;
    private static readonly int Forward = Animator.StringToHash("Forward");
    private static readonly int Turn = Animator.StringToHash("Turn");

    [SerializeField] private float _forwardDumpTime = 0.3f;
    [SerializeField] private float _turnDumpTime = 0.1f;
    [SerializeField] private float _movingTurnSpeed = 360f;
    [SerializeField] private float _stationaryTurnSpeed = 180f;

    private bool _isRotating;
    private List<Vector3> _path;

    private void Awake()
    {
        _animator = GetComponent<Animator>();
        _agent = GetComponent<NavMeshAgent>();
        _agent.updateRotation = false;
        _rigidbody = GetComponent<Rigidbody>();
        _rigidbody.constraints = RigidbodyConstraints.FreezeRotationX | RigidbodyConstraints.FreezeRotationY |
                                 RigidbodyConstraints.FreezeRotationZ;
    }

    private void Update()
    {
        if (!_isRotating)
        {
            UpdateAnimator(_agent.remainingDistance > _agent.stoppingDistance ? _agent.desiredVelocity : Vector3.zero);
        }
    }

    public void MoveTo(Vector3 target)
    {
        _agent.SetDestination(target);
        StartCoroutine(RotateToNextPosition());
    }

    private IEnumerator RotateToNextPosition()
    {
        _agent.isStopped = true;
        _isRotating = true;
        while(rotateAngle > 0.1f)
        {
            _animator.SetFloat(Turn, rotateAngle);
            yield return null;
        }
        _isRotating = false;
        _agent.isStopped = false;
    }

    private float rotateAngle => Vector3.Angle(transform.forward, _agent.steeringTarget) / 180f;

    private void UpdateAnimator(Vector3 velocity)
    {
        float turnAmount = 0f;
        float forwardAmount = 0f;

        if (velocity != Vector3.zero)
        {
            if (velocity.magnitude > 1f)
            {
                velocity.Normalize();
            }

            velocity = transform.InverseTransformDirection(velocity);

            turnAmount = Mathf.Atan2(velocity.x, velocity.z);
            forwardAmount = velocity.z;
            float turnSpeed = Mathf.Lerp(_stationaryTurnSpeed, _movingTurnSpeed, forwardAmount);

            transform.Rotate(0, turnAmount * turnSpeed * Time.deltaTime, 0f);
        }

        _animator.SetFloat(Forward, forwardAmount, _forwardDumpTime, Time.deltaTime);
        _animator.SetFloat(Turn, turnAmount, _turnDumpTime, Time.deltaTime);
    }

    private void OnDrawGizmos()
        {
            if (_path != null && _navMeshAgent)
            {
                Gizmos.color = Color.blue;
                for (var i = 0; i < _path.Count - 1; i++)
                {
                    Gizmos.DrawLine(_path[i], _path[i + 1]);
                }
                Gizmos.color = Color.green;
                Gizmos.DrawWireSphere(_navMeshAgent.steeringTarget, 0.2f);
            }
            Gizmos.color = Color.red;
            Gizmos.DrawLine(transform.position, transform.position + transform.forward);
        }
}

The calculated angle value is very strange and I don’t know why. On the picture below I have drawn a red line for transform.forward, a blue line for path and a green wired sphere for _navMeshAgent.steeringTarget. The angle between transform.forward and _navMeshAgent.steeringTarget is 23 degrees without adjusting the value (angle / 180 => value between 0 and 1 ).

640×572 92.9 KB

476×601 38.6 KB

What am I doing wrong? How can I properly calculate the angle and rotate the agent to the path?

Thank you in advance and sorry for my English :slight_smile:

2

FUUUU!!!

I don’t know why, but code below is working :smiley:

public void MoveTo(Vector3 target)
{
    _agent.SetDestination(target);
    StartCoroutine(RotateToNextPosition());
}

private IEnumerator RotateToNextPosition()
{
    _agent.isStopped = true;
    yield return null;
    print(rotateAngle);
    _agent.isStopped = false;
}

private float rotateAngle
{
    get
    {
        Vector3 direction = _agent.steeringTarget - transform.position;
        return Vector3.SignedAngle(transform.forward, direction, Vector3.up) / 180f;
    }
}

Only need to do is turn the agent to the desired angle through the animation.

3

I’ve got the solution, but it’s like an ugly hackaround. For correct calculation of the angle needs to skip at least 1 frame after stopping the agent.

private void Update()
{
    if (!_isRotating)
    {
        UpdateAnimator(_agent.remainingDistance > _agent.stoppingDistance ? _agent.desiredVelocity : Vector3.zero);
    }
}

public void MoveTo(Vector3 target)
{
    _agent.SetDestination(target);
    StartCoroutine(RotateToNextPosition());
}

private IEnumerator RotateToNextPosition()
{
    _agent.isStopped = true;
    _isRotating = true;
    _rigidbody.detectCollisions = false;
    yield return null;
    _animator.SetFloat(Turn, rotateAngle);
    while (Mathf.Abs(rotateAngle) > 0.1f)
    {
        yield return null;
    }
    _animator.SetFloat(Turn, 0f);
    _rigidbody.detectCollisions = true;
    _isRotating = false;
    _agent.isStopped = false;
}

private float rotateAngle
{
    get
    {
        Vector3 direction = _agent.steeringTarget - transform.position;
        return Vector3.SignedAngle(transform.forward, direction, transform.up) / 180f;
    }
}

If anyone knows how to make this code better, please let me know.

2 Likes