I just noticed there'd been comments on my build photo, so I'll explain I built it on a Solido SD300 using a mix of white and transparent PVC.
The parts were oriented to create a transparent 'band' through the middle of each part, which acts as a light pipe when the sphere is assembled. The right-hand picture shows two parts on a light table as illustration.
These are 50% reduced to take advantage of the SD300's higher resolution, so t
he pieces are quite small.