unity圆内随机一个点
/// <summary>
/// 根据半径随机出园内的点
/// </summary>
/// <param name="vRadius"></param>
/// <returns></returns>
public static Vector2 GetRandomInCircle(float vRadius)
{
var randomValue = Random.Range(0f, 1f);
var r = Mathf.Sqrt(randomValue) * vRadius;
randomValue = Random.Range(0f, 1f);
var theta = 2 * Mathf.PI * randomValue;
//生成x，y坐标，
var x = r * Mathf.Cos(theta);
var y = r * Mathf.Sin(theta);
return new Vector2(x, y);
}