Random.InitState

Parameters

Description

Initializes the random number generator state with a seed.

The random number generator is not truly random, but produces numbers in a preset sequence (the values in the sequence "jump" around the range in such a way that they appear random for most purposes).

The point in the sequence where a particular run of pseudo-random values begins is selected using an integer called the seed value. This prevents the same run of values from occurring each time a game is played and thus avoids predictable gameplay. It is sometimes useful to produce the same run of pseudo-random values on demand by setting the seed yourself.

You might set your own seed, for example, when you generate a game level procedurally. You can use randomly-chosen elements to make the Scene look arbitrary and natural but set the seed to a preset value before generating. This will make sure that the same "random" pattern is produced each time the game is played. This can often be an effective way to reduce a game's storage requirements - you can generate as many levels as you like procedurally and store each one using nothing more than an integer seed value.

The seed is randomly initialized at startup (see Random for more information on this) but if you want to randomize it later on, you can use Random.InitState((int)DateTime.Now.Ticks).

The seed cannot be retrieved once set - the pseudorandomization algorithm stores its internal state in a more complex set of numbers. However, this state can be loaded and stored via the state property, which works with the opaque but serializable State.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    private float[] noiseValues;
    void Start()
    {
        Random.InitState(42);
        noiseValues = new float[10];
        for (int i = 0; i < noiseValues.Length; i++)
        {
            noiseValues[i] = Random.value;
            Debug.Log(noiseValues[i]);
        }
    }
}