GameObject text = new GameObject();

        text.transform.position = Camera.main.transform.position + Camera.main.transform.forward * 5.0f;

        //text.transform.position = Vector3.zero;

        text.AddComponent<TextMesh>();

        var style = text.GetComponent<TextMesh>();

        style.text = "3D Text";

        style.fontSize = 50;

        //显示大小与fontSize、characterSize、距离有关

        style.characterSize = 0.05f;

        style.anchor = TextAnchor.MiddleCenter;