Basic Infinite Vertical Sprite Spawning

Posted by ZheX on 21:36
Today I'll show you something that I use for my own game, Chains!

I'll show you how to infinitely (and semi-randomly) spawn sprites vertically! First off we'll declare some of the things we need. I use orbs in my game, but you should feel free to change anything at all

private GameObject lastOrb;
private Vector2 pos;

//Define the rage in which each object is allowed to spawn
public float fromY;
public float toY;
public float fromX;
public float toX;

public GameObject orbPrefab;
 
//If you want more than one gameObject to spawn declare them aswell and set them in the editor.
public GameObject pinkOrbPrefab;
public GameObject redOrbPrefab;
public GameObject blueOrbPrefab;

Now we need to set the first sample point for the script to work.

void SampleGenerate()
{
 if(lastOrb == null)
 {
 // Here i have a single orb preplaced as a starting point for the script.
 // The name of the object is what you put in GameObject.Find(), it should be unique.
 lastOrb = GameObject.Find("OrbFirst");
 }
}

With a first point of reference we're going to start out

void SampleGenerate()
 {
  if(lastOrb == null)
  {
   lastOrb = GameObject.Find("OrbFirst");
  }
  pos = lastOrb.transform.position;
  pos.y += Random.Range(fromY,toY);
  pos.x += Random.Range(fromX,toX);
  
  InstOrb();
 }

//Here you just select a random range of numbers depending on how many items you have.
//I want my standard orbPrefab to be spawned much more often then my other orbs so it has a 7 in 10 chance.
void InstOrb()
 {
  int Select = Random.Range(0,10);

  switch(Select)
  {
  case 0:
   
   lastOrb = Instantiate(orbPrefab,pos,Quaternion.identity) as GameObject;
   break;

  case 1:
   lastOrb = Instantiate(pinkOrbPrefab,pos,Quaternion.identity) as GameObject;
   break;

  case 2:
   lastOrb = Instantiate(blueOrbPrefab,pos,Quaternion.identity) as GameObject;
   break;

  case 3:
   lastOrb = Instantiate(redOrbPrefab,pos,Quaternion.identity) as GameObject;
   break;

  default:
   lastOrb = Instantiate(orbPrefab,pos,Quaternion.identity) as GameObject;
   break;

  }
 }

Now all we have left to do is utilize the script in our Update function. I don't recommend just keeping it in the Update function as it will slow your game down dramatically. I recommend setting a cycle for it to run once.

Cycle:
void Start()
{
 //Amount of objects to spawn/cycles to run
 int cycles = 10;
 for(int i = 0; i < cycles; i++)
 {
  SampleGenerate();
 }
}
OR [!SLOW WARNING!] Infinite: 
void Update()
{
  SampleGenerate();
}
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