i rendered this character with mental ray and there's some little black pixels on her dress. it is pretty weird i couldnt get it off. i used layered shader for her dress, i tried using just plain lambert, remove bump map, change MR setting but the black pixel still persist. i checked the polygon, there's no overlapping faces whatsoever. i'm baffled. please if anyone face this problem before, share with me your solution if you ever manage to solve it.