Resolved HowTo: Object move left and right at spawn position

Hey! I'm trying to make my target move left and right at the position that its randomly instantiated to with my Game Manager script. I'm currently using this for object movement:

Code (CSharp):

1. private float moveSpeed = 10;
2.     private bool movingLeft;
3.  
4.     void Start()
5.     {
6.         movingLeft = true;
7.     }
8.     void Update()
9.      {
10.          if (movingLeft == true)
11.          {
12.              transform.Translate(Vector3.left * moveSpeed * Time.deltaTime);
13.              if (transform.position.x <= - 4) movingLeft = false;
14.          }
15.          else
16.          {
17.              transform.Translate(Vector3.right * moveSpeed * Time.deltaTime);
18.              if (transform.position.x >= + 4) movingLeft = true;
19.          }
20.      }

The problem with this is that the spawned object goes to global 0X coord and moves between -4x and +4x there instead of moving at the position that it was randomly spawned to.

I also tried to make public float posX; with posX = transform.position.x; variable at void start and doing "if (posX <= - 4) movingLeft = false;...." instead, but then they kept moving on -x Axis to infinity and beyond. What am I doing wrong? How to fix it? Beginner here, so please explain it clearly if possible Thank you in advance!

EDIT: i dont know how to make the script look more readable here..

 

Vector3.left is a hardcoded value of (-1, 0, 0). That's why your object is moving from the center of the coordinate system.
Use something like the following:

transform.Translate(transform.position.x + Vector3.left * moveSpeed * Time.deltaTime

The code above simply adds your current position before moving the object.

 

There is an option to insert code into your post so it's more readable.

 

Hey! I tried this method and I got this error:
Error CS0019 Operator '+' cannot be applied to operands of type 'float' and 'Vector3'

I also tried to change:

Code (CSharp):

1. transform.Translate(transform.position.x + Vector3.left * moveSpeed * Time.deltaTime

Into this:

Code (CSharp):

1. transform.position += Vector3.left * moveSpeed * Time.deltaTime;

But the result remained the same


Tried a few different ways trying to make it work and googling how to convert float to vector3 etc but im still struggling..

And thank you Jnsptz for the tip!

 

Try this.

Code (CSharp):

1. transform.Translate((transform.position + Vector3.left) * (moveSpeed * Time.deltaTime));

 

Hey! Tried the code you mentioned and it sent my objects flying to space at a super high speed the moment they were spawned

I also tried this on the moveleft:

Code (CSharp):

1. transform.Translate(Time.deltaTime * -moveSpeed, 0, 0, Space.Self);

but the results remained yet the same

Could the problem be on these lines?

Code (CSharp):

1.  if (transform.position.x <= -4)
2. if (transform.position.x >= 4)

 

Do you really want -4 and 4? That would suggest the object is spawned at 0, 0, 0 and you want it to move back and forth by four units.

This might be better. Keep track of the initial spawn position and move the object based on a certain offset, ex. original X position +/- 4 units.

This should move it at 1 unit per second. You can always use (Time.deltaTime * movementSpeed) if you want to speed it up.

Code (CSharp):

1. private float moveSpeed = 10;
2.  
3. private Vector3 initialSpawnPosition;
4.  
5. private bool movingLeft;
6.  
7. void Start()
8. {
9.     initialSpawnPosition = transform.position;
10.     movingLeft = true;
11. }
12.  
13. void Update()
14. {
15.     if (movingLeft)
16.     {
17.         transform.Translate((transform.position + Vector3.left) * Time.deltaTime);
18.  
19.         if (transform.position.x == initialSpawnPosition.x - 4.0f)
20.         {
21.             movingLeft = false;
22.             movingRight = true;
23.         }
24.     }
25.  
26.     if (movingRight)
27.     {
28.         transform.Translate((transform.position + Vector3.right) * Time.deltaTime);
29.  
30.         if (transform.position.x == initialSpawnPosition.x + 4.0f)
31.         {
32.             movingRight = false;
33.             movingLeft = true;
34.         }
35.     }
36.  
37. }

 

Hey! Thank you a ton, your suggestion once again made my object fly upwards but with a little tweak to it i was finally able to made it work the way i intended. Here is my final code, making the spawned objects move left to right on x axis at the spot they were instantiated on!

Code (CSharp):

1.  
2.     private Vector3 initialSpawnPosition;
3.     private float moveSpeed = 10;
4.     private bool movingLeft;
5.  
6.  
7.     void Start()
8.     {
9.         initialSpawnPosition = transform.position;
10.         movingLeft = true;
11.  
12.        
13.     }
14.     void Update()
15.     {
16.  
17.          
18.         if (movingLeft)
19.         {
20.             transform.Translate(Vector3.left * Time.deltaTime * moveSpeed);
21.  
22.             if(transform.position.x <= initialSpawnPosition.x - 4.0f)
23.             {
24.                movingLeft = false;
25.             }
26.         }
27.         else
28.         {
29.             transform.Translate(Vector3.right * Time.deltaTime * moveSpeed);
30.  
31.             if (transform.position.x >= initialSpawnPosition.x + 4.0f)
32.              {
33.                movingLeft = true;
34.              }
35.         }
36.          
37.        
38.    

 

Just realised I made the mistake of adding the transform position when moving which would constantly increase the speed every frame.

Code (csharp):

1. transform.position + Vector3.left

So if the position was 10, 10, 10 it would move it by 11 units per second. Then 12 units/second...etc. Multiplying that by movement speed no doubt made it worse because it was probably moving at 50+ units per second.

Glad you got it to work.