Custom Fill Origin

I'm working with a circle I want to segment into 16 different pie pieces.

When a piece is interacted with, it will have an animation that plays, depending on the side. I have a sprite sheet made for the animation already.

I'm using the UI Image component, set to filled, fill method radial 360, Fill Origin. The fill amount is a .0625 for each segment, because 16/1 = .0625.

I have a perfect circle segmented into 16 pieces. the problem is the 16 pieces are all the same part of the circle, not the circle as a whole, since the FILL ORIGIN is always bottom.

My question is , is it possible to have a custom Fill Origin for an image, if so how would i approach coding it?

if anyone has a different way to segment a circle please also I would love that. I've cut up circles before but it's almost impossible to put them perfectly together in unity after.!alt text