MaxScript render ignores Vray settings.

Hi there all! I'm new in MaxScript, I have a little problem.

I created a little code to change text to text shape and render a short animation. It works but ignore my Vray setting, why? This is the code:

(
c = "ABC";
for i = 1 to c.count do
(
	$textshape.text = c[i];
	frames = interval 0f 20f;
	render outputfile:(c[i]+"-.png") framerange: frames vfb:off progressbar:on;
)
)

What I should put? Thanks!