Gameobject to "run" away from another on collide trigger

Unity Engine
1

So… I have a gameobject with a collider trigger setup. I want it to detect while another specific gameobject (tag “player”) is within the collider, to turn and run away.

I have the movement working, however the rotation is not working. It appears to “flicker”, I believe because it is continuously recalculating the angle of transform.forward back and forth.

Note, that I want the gameobject to continue running away, until the player is out of the sphere collider (like it is “escapaing”).

Here is my code currently:

    void OnTriggerStay(Collider CollisionObject)
    {

        if (CollisionObject.tag == "Player")
        {

        // Rotate gameobject to face "away" from the player who entered the collider
            Vector3 targetDirection = CollisionObject.transform.position - transform.position;
            Vector3 newDirection = Vector3.RotateTowards(transform.forward, targetDirection, -180, 10);
            Debug.DrawRay(transform.position, newDirection, Color.red);
            transform.rotation = Quaternion.LookRotation(newDirection);

        // (This section works as expected) script to move gameobject away from player.
            transform.position = Vector3.MoveTowards(transform.position, CollisionObject.transform.position, -1 * walkSpeed * Time.deltaTime);
        }
    }

Appreciate any advice on what I am doing wrong…

2

Which object is the player and which is the running object?

One thing I see that is weird is your 3rd argument to Vector3.RotateTowards: -180

Vector3.RotateTowards takes an angle in radians. 180 radians is almost 29 full rotations! You probably want to use -Mathf.PI as your argument, which is equal to 180 degrees of rotation. Why did Unity use radians for Vector3.RotateTowards? Beats me!

3

Sorry, the collision object with tag player, is player. The script is attached to the running object.

Thanks for the comment regarding radians, I will have a play with that also.

A question regarding RotateTowards though, how can I tell it to rotatetowards away from the player? I guess I need to calculate the direction between the two objects to determine the angle?

4

SO if CollisionObject is the player and transform is the “runner”, then accoding to this:Vector3 targetDirection = CollisionObject.transform.position - transform.position; “targetDirection” will be a Vector pointing from the runner towards the player.

But then you’re using a negative value in RotateTowards so this should cancel out to rotating away from the player. However it would be simpler if you got rid of the double negative:

    void OnTriggerStay(Collider CollisionObject)
    {
        if (CollisionObject.tag == "Player")
        {
            // Rotate gameobject to face "away" from the player who entered the collider
            Vector3 targetDirection = transform.position - CollisionObject.transform.position;
            Vector3 newDirection = Vector3.RotateTowards(transform.forward, targetDirection, Mathf.PI, 10);
            Debug.DrawRay(transform.position, newDirection, Color.red);
            transform.rotation = Quaternion.LookRotation(newDirection);
            // (This section works as expected) script to move gameobject away from player.
            transform.position = Vector3.MoveTowards(transform.position, CollisionObject.transform.position, -1 * walkSpeed * Time.deltaTime);
        }
    }

I’m not sure that will fix your problem though… The cheaty way would be this:

    void OnTriggerStay(Collider CollisionObject)
    {
        if (CollisionObject.tag == "Player")
        {
            // Rotate gameobject to face "away" from the player who entered the collider
            Vector3 targetDirection = transform.position - CollisionObject.transform.position;
            Debug.DrawRay(transform.position, targetDirection, Color.red);
            transform.rotation = Quaternion.LookRotation(targetDirection);
            // (This section works as expected) script to move gameobject away from player.
            transform.position = Vector3.MoveTowards(transform.position, CollisionObject.transform.position, -1 * walkSpeed * Time.deltaTime);
        }
    }