I'm really sorry to bump this thread again but I'm almost at my wit's end with this. I have shoestring shaders working properly afterall. The black area is just due to the distortion of the SS glass shader and me not having a back wall in my scene. I feel like taking a photo of my real glass on a coaster at the same angle as my renders just to prove how little refraction there is. It's absolutely nothing like any of the glass presets in Carrara or shoestring. I've tried minimizing the distortion by changing the different properties including the fresnel effect properties and the top half of the glass looks fine, but not the bottom half. I'm sure if I changed it to a wine glass it'd be fine but I'm determined to get this one right.

If anyone is interested in my little plight could I perhaps send someone my scene file so they can prove me wrong about this? I'm just not sure subtle refraction is possible in the Carrara shader tree, but hopefully it's my lack of knowledge or my simple model at fault.

So if someone wouldn't mind please let me know. Cheers. :)