How to make bubbles float across the screen

Questions & Answers
1

Hi,

I have a 2D bubble game where bubbles spawn from the same position on the left side of the screen then float off to the right in a slight up and down motion. Here is the code attached to the bubble once it has been spawned:

    private float amplitude = .4f;
private float speed = 1.5f;
private float tempY;
private float tempX;
private Vector3 tempPos;
void Start ()
{
	tempY = transform.position.y;
	tempX = transform.position.x;
}

void Update ()
{		
		tempPos.y = tempY + amplitude * Mathf.Sin (speed * Time.time);
		tempPos.x += .05f;
		transform.position = tempPos;	
}

The first bubble spawns in the right position and moves fine, but each bubble after that spawns slightly higher or lower then the starting position seemingly to match the y position of the first bubble.

I need each bubble to start from the exact same position then float of to the right moving up and down independent from other bubbles.

Please help! Thanks!

2

I figured it out,

    private float amplitude = .4f;
 private float speed = 1.5f;
 private float tempY;
 private float tempX;
 private Vector3 tempPos;
private float startTime;


 void Start ()
 {
     tempY = transform.position.y;
     tempX = transform.position.x;
     startTime = Time.time;
 }

 void Update ()
 {        

float newTime = Time.time - startTime;
         tempPos.y = tempY + amplitude * Mathf.Sin (speed * startTime);
         tempPos.x += .05f;
         transform.position = tempPos;    
 }

I had to get the difference between start time and current time.