Random.insideUnitCircle

説明

半径 1 の円の内部のランダムな点を返します（読み取り専用）

using UnityEngine;

public class ScriptExample : MonoBehaviour
{
    void Start()
    {
        // Sets the position to be somewhere inside a circle
        // with radius 5 and the center at zero. Note that
        // assigning a Vector2 to a Vector3 is fine - it will
        // just set the X and Y values.
        transform.position = Random.insideUnitCircle * 5;
    }
}