Challenge: Developing a Video Game in one Week — Day 2

Revisiting Unity and C#

What’s new

I added three enemies/mobs one that follows the player slowly, I added a homing missile, and an enemy that just follows the outline of the map.

Slow Follow

For the slow follow it’s just a classic code using the distance calculation and the Vector2.MoveTowards function.

public float Speed;
public float radius;

public bool FoundPlayer;
private GameObject player;
public float distance;

void Start(){
      try{
        player = GameObject.FindWithTag("Player");
        FoundPlayer = true;
      }
      catch{
        FoundPlayer = false;
      }      
}

void Update(){
    if(FoundPlayer){
        distance = Vector2.Distance(transform.position, player.transform.position);
        Vector2 direction = player.transform.position - transform.position;
        direction.Normalize();
        float angle = Mathf.Atan2(direction.y, direction.x) * Mathf.Rad2Deg;

        if(distance > radius){
            transform.position = Vector2.MoveTowards(this.transform.position, player.transform.position, Speed * Time.deltaTime);
            transform.rotation = Quaternion.Euler(Vector3.forward * angle);
        }
    }
}

Path Finder

For this mob I kinda feel it’s just a scam, If I had more time I’d look into linear math to make this look more professional. I’m just using raycasts to see which wall am I on, and I just base movement of that.

public Transform up;
public Transform down;
public Transform left;
public Transform right;

public Transform TopRight;
public Transform TopLeft;
public Transform BottomRight;
public Transform BottomLeft;

private Rigidbody2D rb;
public float length;
public float Speed;
public LayerMask ground;

    void Start(){
        rb = GetComponent<Rigidbody2D>();
    }

    void FixedUpdate(){
        
        RaycastHit2D UpHit = Physics2D.Raycast( up.transform.position, Vector2.up,  length, ground );
        RaycastHit2D DownHit = Physics2D.Raycast( down.transform.position, Vector2.down, length, ground);
        RaycastHit2D RightHit = Physics2D.Raycast( right.transform.position, Vector2.right, length, ground);
        RaycastHit2D LeftHit = Physics2D.Raycast( left.transform.position, Vector2.left, length, ground);
        
        RaycastHit2D BottomRightCorner = Physics2D.Raycast( BottomRight.transform.position, new Vector2(1,-1) , length*5, ground);
        RaycastHit2D BottomLeftCorner = Physics2D.Raycast( BottomLeft.transform.position, new Vector2(-1,-1) , length*5, ground);

        RaycastHit2D TopRightCorner = Physics2D.Raycast( TopRight.transform.position, new Vector2(1,1) , length*5, ground);
        RaycastHit2D TopLeftCorner = Physics2D.Raycast( TopLeft.transform.position, new Vector2(-1,1) , length*5, ground);


        if(UpHit){
            rb.velocity = Vector2.left * Speed;
        }
        if(DownHit){
            rb.velocity = Vector2.right * Speed;
        }
        if(RightHit){
            rb.velocity = Vector2.up * Speed;
        }
        if(LeftHit){
            rb.velocity = Vector2.down * Speed;
        }
        if(UpHit && RightHit){
            rb.velocity = Vector2.left * Speed;
        }
        if(DownHit && LeftHit){
            rb.velocity = Vector2.right * Speed;
        }
        if(BottomRightCorner && !UpHit && !DownHit && !RightHit && !LeftHit){
            rb.velocity = Vector2.right * Speed;
        }
        if(BottomLeftCorner && !UpHit && !DownHit && !RightHit && !LeftHit){
            rb.velocity = Vector2.down * Speed;
        }

        if(TopLeftCorner && !UpHit && !DownHit && !RightHit && !LeftHit){
            rb.velocity = Vector2.left * Speed;
        }
    }

Homing Missile

Foe the missile it’s important that you add a Rigidbody2D, for the other I’m pretty sure you’d be ok with just colliders. Now this one I just straight up got the code from brackeys, awesome channel.

public float Speed = 5f;
    public float rotateSpeed = 200f;
    private GameObject player;
    private Rigidbody2D rb;

    void Start(){
        rb = GetComponent<Rigidbody2D>();
        player = GameObject.FindWithTag("Player");
    }

    // Update is called once per frame
    void FixedUpdate(){
        
        Vector2 direction = (Vector2)player.transform.position - rb.position;
        direction.Normalize();
        float rotate  = Vector3.Cross(direction, transform.up).z;
        
        rb.angularVelocity = -rotate * rotateSpeed;

        rb.velocity = transform.up * Speed;

    }