I wasn't actually joking about the "discrete" part, although it makes for a nice pun (I think the word you were thinking of is spelled "discreet", though). Discrete differential geometry is a fairly new discipline which analyzes the properties of meshes and such not as approximations of continuous entities like classical differential geometry would, but as objects of their own. Google it and you will see.

-- I'm not mad at you, just Westphalian.