Yes it does exist in the empty hand forms, though to a large degree I suspect it will probably depend on the style of wing chun you do.It exists in the WC pole form. But does it exist in the WC open hand form?
Something like this - counter-clock half circle, clockwise half circle.
In open hand, it may look like this.
It is a feature of the Yip Man wing chun I learned; and It is most certainly a central component of Sum Nung wing chun I learn. That said it doesn't appear, from what I have seen at least, to be that prominent in most Yip Man wing chun.