error CS1612

This is my camera follow code for a 2D game. The problem I am having is that I am getting the error:

error CS1612: Cannot modify a value type return value of `UnityEngine.Transform.position'. Consider storing the value in a temporary variable

It has to do with the Clamp camera but I am not sure how to fix this.

Any help would be much appreciated.

Code (CSharp):

1.  
2.     public Transform Target;
3.     public float moveSpeed = 0.2f;
4.     Camera mainCam;
5.  
6.     void Start ()
7.     {
8.         mainCam = GetComponent<Camera> ();
9.         transform.position.x = Mathf.Clamp(transform.position.x,-10, 10); // to prevent the camera from going past a certain point
10.         transform.position.y = Mathf.Clamp(transform.position.y,-10, 10); // to prevent the camera from going past a certain point
11.     }
12.  
13.     void Update ()
14.     {
15.         mainCam.orthographicSize = (Screen.height / 100f) / 4f;
16.  
17.         if (transform)
18.         {
19.             transform.position = Vector3.Lerp(transform.position, Target.position, moveSpeed) + new Vector3(0, 0, -10);
20.         }
21.     }
22. }
23.  

 

This is quite a common problem which I see a lot of people face. Basically you should correct it to

Code (csharp):

1. Vector3 temp = transform.position:
2.  
3. temp.x = Mathf.Clamp(transform.position.x,-10, 10);
4. temp.y = Mathf.Clamp(transform.position.y,-10, 10);
5.  
6. transform.position = temp;

This error happens because Vector 3 is a struct and transform.position is a getter method

 

Thank you so much!!

 

@NintendoMaster00 Its no problem

 

Thanks again the error went away but the camera will still go past the points I specified

here is my updated code if you know what I did wrong :

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class CameraFollow : MonoBehaviour {
5.  
6.     public Transform Target;
7.     public float moveSpeed = 0.2f;
8.     Camera mainCam;
9.  
10.     void Start ()
11.     {
12.         mainCam = GetComponent<Camera> ();
13.  
14.         Vector3 vect = transform.position;
15.  
16.         vect.x = Mathf.Clamp(transform.position.x,-2f, 5f); // to prevent the camera from going past a certain point
17.         vect.y = Mathf.Clamp(transform.position.y,-9f, 1f); // to prevent the camera from going past a certain point
18.         transform.position = vect;
19.     }
20.  
21.     void Update ()
22.     {
23.         mainCam.orthographicSize = (Screen.height / 100f) / 4f;
24.  
25.         if (transform)
26.         {
27.             transform.position = Vector3.Lerp(transform.position, Target.position, moveSpeed) + new Vector3(0, 0, -10);
28.         }
29.     }
30. }

 

You're clamping the values one time. Start() is called before the first frame an object is rendered on.

Instead, move the clamping to the Update() function, probably after transform.position=Vector3 ect....
Update is called every frame, before the object is rendered.

So, you want.

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class CameraFollow : MonoBehaviour {
5.  
6.     public Transform Target;
7.     public float moveSpeed = 0.2f;
8.     Camera mainCam;
9.  
10.     void Start ()
11.     {
12.         mainCam = GetComponent<Camera> ();
13.  
14.     }
15.  
16.     void Update ()
17.     {
18.         mainCam.orthographicSize = (Screen.height / 100f) / 4f;
19.  
20.         if (transform)
21.         {
22.             transform.position = Vector3.Lerp(transform.position, Target.position, moveSpeed*Time.deltaTime) + new Vector3(0, 0, -10);
23.  
24.             Vector3 vect = transform.position;
25.  
26.             vect.x = Mathf.Clamp(transform.position.x,-2f, 5f); // to prevent the camera from going past a certain point
27.             vect.y = Mathf.Clamp(transform.position.y,-9f, 1f); // to prevent the camera from going past a certain point
28.             transform.position = vect;
29.         }
30.     }
31. }

Also, I added *Time.deltaTime after moveSpeed. This means it will move at a constant rate no matter what your FPS is.

 

Thanks!