Spawning coins randomly in an infinite runner 3d game

Question

I have a 3d infinite runner car racing type game in which the player is stationary and the background moves. In my game I want to spawn coins randomly over time and the coins has to be spawned very much ahead of the player, and the z axis of the coins get reduced keeping y axis constant and x axis values in a random range of -2 and 2. The coins are spawning correctly but they are spawned in an irregular manner. I created four coin game objects in my scene, I want to spawn the 4 coins in a straight line because then the player can easily collect the coins since they are coming in a straight line to the player. The players motion is only in the x axis from -2 to 2. Now my problem is that the coins are spawned irregularly because of that the coins cannot be collected easily by the player. THis is my code:

function Update()
{
    MoveCoin();
}

function MoveCoin()
{
    ReleaseCoin();
    //CoinsOnRoad is an array containing the current coins which are on the road
    //CoinPool is the array of coins
    for(var i:int =0;i<CoinsOnRoad.length;i++)
    {
    var gcoin:GameObject = CoinsOnRoad[i] as GameObject;
    gcoin.transform.position.z-=3*speed*Time.deltaTime;
    if(gcoin.transform.position.z>=-10)
    {
        //Do nothing if the coin is on the visible area of the road. If it becomes invisible
        //remove the coins from CoinsOnRoad Array and insert the coin back to the CoinPool Array
    }
    else
    {
        CoinPool.push(gcoin);
        CoinsOnRoad.remove(gcoin);

    }

    }
}

function ReleaseCoin()
{
    if(CoinPool.length==0)
    {

    }
    else
    {
        var coin:GameObject=CoinPool.shift() as GameObject;
        CoinsOnRoad.push(Instantiate(coin,new Vector3(Random.Range(-2.0,2.0),0.3,30+Random.Range(1,10)),Quaternion .identity));

    }
}

The coins are spawning correctly but in an irregular order. Can someone please help me out? Thanks in advance..Since I'm new to unity, I didn't knew whether even my game logic is correct or not. Can some one correct me with the code if I'm wrong some where in my code.

try without deltatime multiplication – CodeSmile Oct 31 '14 at 08:10 — CodeSmile, Oct 31 '14 at 08:10
@LearnCocos2D It doesnot work.. – njnjnj Oct 31 '14 at 08:16 — njnjnj, Oct 31 '14 at 08:16

score 0 · Answer 1 · answered Nov 06 '14 at 20:52

0

If you want coins to spawn in straight lines it might just help to have them not spawn randomly.

In your loop you're spawning individual coins each with a different random position. Instead you should be randomly selecting the position value and saving it to a variable. You should then use this to spawn multiple coins in a loop.

Like so:

var xPos = Random.Range(-2.0, 2.0);
var forwardOffset = Random.Range(1, 10);
var i = 0;
var lineLength = Random.Range(1, CoinPool.length);
while(i < lineLength) {
    var coin:GameObject=CoinPool.shift() as GameObject;
    CoinsOnRoad.push(Instantiate(coin,new Vector3(xPos, 0.3, 30 + forwardOffset + i), Quaternion.identity));
    i += 1;
}

answered Nov 06 '14 at 20:52

Agumander

676
4
11

I don't want instantiate method, instead I want the object pooling method, since object pooling easy for programming.. – njnjnj Nov 20 '14 at 06:38
Then replace `Instantiate` with a method that returns a coin gameobject using pooling. Object pooling is as simple as `Instantiate`ing a bunch of objects off-screen and keeping track of them in a queue structure. When you want to use an object from the pool you dequeue from that structure and use that object. When you're done with the object move it offscreen and enqueue it instead of using `Destroy`. This coin placement method will work regardless of how you provide the coin object. – Agumander Nov 20 '14 at 16:53

Spawning coins randomly in an infinite runner 3d game

1 Answers1