void FixedUpdate()
    {
        rb.MovePosition(rb.position + (direcao * velocidade * Time.deltaTime));
        Ray raio = Camera.main.ScreenPointToRay(Input.mousePosition);
        RaycastHit impacto;
        Debug.DrawRay(raio.origin, raio.direction);
        if (Physics.Raycast(raio,out impacto, 100, MascaraChao)){
            Vector3 posicaomira = impacto.point - transform.position;
            posicaomira.y = transform.position.y;
            Quaternion novsRotacao = Quaternion.LookRotation(posicaomira);
            rb.MoveRotation(novsRotacao);
        }

    }