Make an object a certain distance from me.

Question

Hello so I have finally got some code working that enables an object to rotate and move towards another object when space bar is pressed. So an object will move to the player when space bar is pressed. Awesome, got that running! however it moves so freakin close to the player! I want it to move a little bit away from the player. Not to close, how can I do that. Here is my code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 
 public class lerpFinal : MonoBehaviour
 {
     //This is a new variable to store a Vector3 Position
     private Vector3 newPosition;
     private bool flagPos;
     public Transform Player;
     public Transform Target; 
 
     //Here we set the current position of the object using transform.position
     private void Awake()
     {
         newPosition = transform.position;
     }
 
     //Here we are running positionChanging function in each framej
     void Update()
     {
         PositionChanging();
         transform.LookAt(Target); 
     }
 
     void PositionChanging()
     {
         //Here is Where the positions are set
         Vector3 positionA = new Vector3(0, 0, 0);
         Vector3 positionB = Player.position;
 
         //Inputing the following keys will allow us to Change the Position
         if (Input.GetKeyDown(KeyCode.Space) && flagPos == false)
         {
             newPosition = positionA;
             flagPos = true;
 
         }
         else if (Input.GetKeyDown(KeyCode.Space) && flagPos == true)
         {
             newPosition = positionB;
             flagPos = false;
         }
       
 
         transform.position = Vector3.Lerp(transform.position, newPosition, Time.deltaTime);
     }
 }

Answer 1

Best Answer

Answer by rainChu · Aug 19, 2018 at 01:26 AM

I think I see what you're trying to do. Instead of Lerping towards the player's actual position, you should find a new position that's close to the player, along a line of sight.

Try this adding this to the bottom of PositionChanging():

 void PositionChanging()
 {
     // ... Original Code as above ....
     
     // Find the amount we have to move in total
     var offset = transform.position - newPosition;

     // Find the direction we have to move in
     var direction = offset.normalized;

     // Add 0.3 units to the newPosition, away from the player
     newPosition += direction * 0.3f;

     // ... Original Code as below ....

     // Now you lerp
     transform.position = Vector3.Lerp(transform.position, newPosition, Time.deltaTime);
 }

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Answer 2

The exact solution here depends on how your game plays, as in is it on a 2D field, 3D, etc, but here's a generic solution you can modify to fit your needs:

 public float dist = 3; // How far to stop (meters)
 public float speed = 1; // How fast to follow (m/s)
 public Transform player; // Reference to player
 protected Vector3 targetPosition = Vector3.zero;
 private bool isFollowing = false;
 [SerializeField]
 private bool debug = false;
 
 void Update ()
 {
     if (isFollowing)
     {
         transform.LookAt (player);
         float dist3 = speed*Time.deltaTime; // How far to move this frame
         float dist2 = Vector3.Distance (targetPosition, transform.position); // Distance from target
         if (dist3>dist2)
         {
             dist3 = dist2;
             isFollowing = false; // At target, stop following. (Optional! Remove to follow forever)
             if (debug) Debug.Log("Reached target!");
         }
         Vector3 direction = (targetPosition-transform.position).normalized;
         transform.position += direction*dist3; // This moves the object each frame.
     }
 
     if (Input.GetKeyDown(KeyCode.Space) && !isfollowing)
     {
         Follow ();
     }
     else if (Input.GetKeyDown(KeyCode.Space) && isfollowing)
     {
         StopFollow ();
     }
 }
 
 
 void Follow ()
 {
     if (debug) Debug.Log("Follow() called");
     float dist2 = Vector3.Distance (player.position, transform.position); // Distance from player
     
     if (dist2 >= dist ) // Don't do anything if its already in range
     {
         isFollowing = true;
         float frac = 1 - (dist/dist2); // How far to travel, converts distances to a fraction
         Vector3 targetPosition = Vector3.Lerp (transform.position, player.position, frac); // Gets position in straight line
     if (debug) Debug.Log("New target:\n" + targetPosition.ToString());
     }
     else
     {
         if (debug) Debug.Log("Follow Cancled!\nAlready in range of target!");
         StopFollow ();
     }
 }
 
 void StopFollow ()
 {
     if (debug) Debug.Log("StopFollow() Called");
     targetPosition = Vector3.zero // Not necessary, but can be nice to have for debugs
     isFollowing = false;
 }

Replace your script with this, it should do what you need, and a lot better than what you currently have. I didn't test it myself, so you just leave a comment if there's any errors you cant fix on your own.

As a side note, you really botched Vector3.Lerp(). Its a somewhat common mistake where it kinda works right, but you should really look in to the proper usage for it. Your usage makes the game play VERY differently and high and low FPS differences.

Make an object a certain distance from me.

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