Player Movement Lerp

Hello, i'm making an android 2d game, i have a problem making the movement, what i want to do is make it that when you shoot bellow yourself / on top of yourself / any side etc. as long as it hits a wall in like some radius it moves you in the opposite way from the rocket (U will understand what i'm trying to make if u have played rocket jump in csgo ). Like a blast that throws you away, i tried to do it this way: Get the pos from place where rocket hit's ground, multiply it by -1 so it's the opposite, and then using Lerp() move the player to that position. But instead of smoothly moving to that position it jumps there instantly or jumps instantly in like midway of the end position (Depends on the t float).

Maybe there is a better way to do it?

Here's my code:

Code (CSharp):

1. public GameObject Player;
2.     public GameObject Rocket;
3.     public GameObject MovePosIndicator;
4.     public bool rocketDetected;
5.     public float MoveDistanceX;
6.     public float MoveDistanceY;
7.     public float MoveSpeed;
8.     public Vector2 MovePosition;
9.  
10.     void Start () {
11.         Player = GameObject.Find ("Player");
12.     }
13.  
14.     void Update () {
15.  
16.         if (Rocket == null) {
17.             rocketDetected = false;
18.         }
19.         if (Rocket != null) {
20.             MoveDistanceX = Rocket.transform.position.x - transform.position.x;
21.             MoveDistanceY = Rocket.transform.position.y - transform.position.y;
22.  
23.             MovePosition.x = MoveDistanceX * -1;
24.             MovePosition.y = MoveDistanceY * -1;
25.  
26.             if (Rocket.GetComponent<Rocket> ().rocketBlewUp) {
27.                 MovePosIndicator.gameObject.transform.position = MovePosition;
28.  
29.                 Player.transform.position = Vector3.Lerp(Player.transform.position, MovePosition, MoveSpeed * Time.deltaTime);
30.             }
31.         }
32.  
33.     }
34.  
35.     void OnTriggerEnter2D(Collider2D other){
36.         if (other.gameObject.tag == "PlayerDetector") {
37.             if (other.transform.parent.gameObject.tag == "RocketShot") {
38.                 Rocket = (other.transform.parent.gameObject);
39.                 rocketDetected = true;
40.             }
41.         }
42.     }
43.  
44.     void OnTriggerStay2D(Collider2D other){
45.         if (other.gameObject.tag == "PlayerDetector") {
46.             if (other.transform.parent.gameObject.tag == "RocketShot") {
47.                 Rocket = (other.transform.parent.gameObject);
48.                 rocketDetected = true;
49.             }
50.         }
51.     }

 

You're using Lerp wrong!

Check out the "Lerp like a pro" link in my signature for how to use lerp properly.

 

You seem to have a host of problems.

1, you are using a Vector2 to handle your position, but you are using Vector3.Lerp with it, that should not work out right for you
2. you seem to not be letting Unity help you out at all with math

Code (csharp):

1.  
2. MovePosition = transform.position - Rocket.transform.position;
3.  // not
4. MoveDistanceX = Rocket.transform.position.x - transform.position.x;
5. MoveDistanceY = Rocket.transform.position.y - transform.position.y;
6.  
7. MovePosition.x = MoveDistanceX * -1;
8. MovePosition.y = MoveDistanceY * -1;
9.  

3.You should examine why you are using Lerp here in the first place.
My guess is that you want to use Lerp to move your player towards the rocket.
To do this, you dont use Lerp at all, you use MoveTowards.

Code (csharp):

1.  
2. Player.transform.position = Vector3.MoveTowards(Player.transform.position, MovePosition,MoveSpeed * Time.deltaTime );
3.  

 

[JOKE]
This should be implemented as a warning message anytime Time.deltaTime is used as parameter with Lerp.
[/JOKE]

 

Why? it's perfectly valid to use lerp with deltatime, assuming that's the behaviour you're going for. Perhaps some people desire a curve.

 

@hippocoder

About the OP implementation:

Code (CSharp):

1. Player.transform.position = Vector3.Lerp(Player.transform.position, MovePosition, MoveSpeed * Time.deltaTime);

If you let yourself being mislead by the variable naming, you would think that MoveSpeed*Time.deltaTime is a step for the current frame. Therefore you can conclude that the intention is to move towards MovePosition at constant speed, which is not what this line will effectively do.

More generally, this way of using Lerp is for doing some damping.
Most of the time Lerp is used with Time.deltaTime is to implement some damping towards a target position:

Code (CSharp):

1. transform.position = Vector3.Lerp(transform.position, targetPosition, dampingFactor* Time.deltaTime);

When that is used in Update, the presence of Time.deltaTime might mislead you into thinking that the damping is frame-rate-independent, which is also wrong: the damping will be slower with a lower framerate. (Thought, this is not the case with FixedUpdate since Time.deltaTime is constant).

Above all, there is a method to do damping properly:
https://docs.unity3d.com/ScriptReference/Vector3.SmoothDamp.html

 

Yeah - but throwing an error for use of DeltaTime is a bit out there & impossible to police

 

That was intended as a joke (I've updated my post with [JOKE]), not an actual feature suggestion.

But considering how frequent this way of using lerp is, it seems that there is something to be done.

 

Uh, thank you all! I feel so stupid right now tho' And the main problem was that i make it do the lerp only like in 1 frame... Bcz of this:

Code (CSharp):

1.  if(Rocket !=null){
2.      if(Rocket.GetComponent<Rocket>().rocketBlewUp){
3.           //~1 frame
4.      }
5. }