Infinite Parallax Background

Questions & Answers
1

Ok, so i have an idea for an infinite parallax background but have no idea how to code it, i’m pretty new to C#, so…

the player has the camera attached to them so as they move, they appear stationary but they are moving through the world. at the start of the level i want it to spawn an object at a random location inside the cameras view port.

i’m actually stuck right here…

public float distance;
	public float lB;
	public float rB;
	public float tB;
	public float bB;
	public float randomX;
	public float randomY;
	
	// Update is called once per frame
	void Update () 
	{
		distance = (transform.position - Camera.main.transform.position).z;

		randomX = Random.Range (-10, 10);
		randomY = Random.Range (-6, 6);

		lB = Camera.main.ViewportToWorldPoint (new Vector3 (0, 0, distance)).x;
		rB = Camera.main.ViewportToWorldPoint (new Vector3 (1, 0, distance)).x;

		bB = Camera.main.ViewportToWorldPoint (new Vector3 (0, 0, distance)).y;
		tB = Camera.main.ViewportToWorldPoint (new Vector3 (0, 1, distance)).y;

	
		if (bB == 0) 
		{
			transform.position = new Vector3 (randomX, tB, -20);		
		} 
		else if (tB == 0) 
		{
			transform.position = new Vector3 (randomX,bB,-20);
		}
	}

from what i understand, the if statement is the problem, its not executing the transform.position.

I haven’t even gotten to making a few hundred of these stars appear and all execute this code.

2

I don’t understand how this code is giving you a random position within the camera view. Here are a couple of points:

  • Never directly compare two floating point values…especially if one is the result of any kind of calculation. You can use Mathf.Approximately() to compare them.
  • Not sure it makes in difference, but the integer version of Random.Range() is exclusive of the upper value. So for example RandomX will get values from -10 to 9, and only integer values. I think you want this instead: randomX = Random.Range(-10.0f, 10f);

Now if you are trying to produce random positions in the view of the camera at ‘distance’ from the camera, you can use these two lines:

Vector3 pos = new Vector3(Random.Range(0.0, 1.0), Random.Range(0.0, 1.0), distance);
transform.position = Camera.main.ViewporToWorldPoint(pos);
3

Wow, thank you so much, I’ve been struggling with this all day, haha, i cant believe i overlooked something so simple, it works like a charm, although the sprites clump up when i travel in both the X and Y directions at the same time but i can live with that for now.