gwoo pointed me to this sample code: https://github.com/pointlessjon/sphere
It's actually the most useful doc I've seen so far. Sorry to be blunt, but it was more useful than the whole existing manual. I recommend putting a link to this code prominently on the web site, including on the first page of the manual.
I'm sorry that this ticket is anwsered this late. UnionOfRad/sphere (via pointlessjon/sphere) is a really great project. However it's been unmaintained since 2012 and probably contains now incompatible code.