c# - How to move 2D Object within camera view boundary

Question

I have a scene that my camera doesn't follow my player. When player reaches the end of camera I want player to can't go further (out of camera view). How can I do this?

My codes for movement

public class PlayerBlueController : MonoBehaviour {

public float speed;
private float x;



// Use this for initialization
void Start () {


}

// Update is called once per frame
void FixedUpdate () {

    x = Input.GetAxis ("Horizontal") / 100 * speed;
    transform.Translate (x,0,0);

}
}

As you can see from this. It gets out of camera's view.

Answer 1

I noticed you used a Collider2D. You should be using Rigidbody2D.MovePosition instead of transform.Translate or you'll likely run into issues when transform.Translate is used.

1.Take the final move position and convert it to new position in ViewPortPoint with Camera.main.WorldToViewportPoint

2.Apply a limit with Mathf.Clamp to the result in #1.

3.Convert the ViewPortPoint back to world point with Camera.main.ViewportToWorldPoint.

4.Finally, move it with Rigidbody2D.MovePosition.

---

The code below is modified from this answer to include restriction to screen boundary.

Move without Rigidbody:

Use only if collision and physics are NOT required:

public float speed = 100;
public Transform obj;

public void Update()
{
    float h = Input.GetAxis("Horizontal");
    float v = Input.GetAxis("Vertical");

    //Move only if we actually pressed something
    if ((h > 0 || v > 0) || (h < 0 || v < 0))
    {
        Vector3 tempVect = new Vector3(h, v, 0);
        tempVect = tempVect.normalized * speed * Time.deltaTime;


        Vector3 newPos = obj.transform.position + tempVect;
        checkBoundary(newPos);
    }
}

void checkBoundary(Vector3 newPos)
{
    //Convert to camera view point
    Vector3 camViewPoint = Camera.main.WorldToViewportPoint(newPos);

    //Apply limit
    camViewPoint.x = Mathf.Clamp(camViewPoint.x, 0.04f, 0.96f);
    camViewPoint.y = Mathf.Clamp(camViewPoint.y, 0.07f, 0.93f);

    //Convert to world point then apply result to the target object
    obj.position = Camera.main.ViewportToWorldPoint(camViewPoint);
}

Move Object with Rigidbody2D:

Use if collision and physics are required:

public float speed = 100;
public Rigidbody2D rb;

public void Update()
{
    float h = Input.GetAxis("Horizontal");
    float v = Input.GetAxis("Vertical");

    //Move only if we actually pressed something
    if ((h > 0 || v > 0) || (h < 0 || v < 0))
    {
        Vector3 tempVect = new Vector3(h, v, 0);
        tempVect = tempVect.normalized * speed * Time.deltaTime;

        //rb.MovePosition(rb.transform.position + tempVect);

        Vector3 newPos = rb.transform.position + tempVect;
        checkBoundary(newPos);
    }
}

void checkBoundary(Vector3 newPos)
{
    //Convert to camera view point
    Vector3 camViewPoint = Camera.main.WorldToViewportPoint(newPos);

    //Apply limit
    camViewPoint.x = Mathf.Clamp(camViewPoint.x, 0.04f, 0.96f);
    camViewPoint.y = Mathf.Clamp(camViewPoint.y, 0.07f, 0.93f);

    //Convert to world point then apply result to the target object
    Vector3 finalPos = Camera.main.ViewportToWorldPoint(camViewPoint);
    rb.MovePosition(finalPos);
}