[crabmusket]

I was introduced to it, if I remember correctly, via a post on The Dark Mod forums (a Thief-like mod engine). The pattern in question was "positive outdoor space", on the importance of creating places between buildings, rather than just plopping discrete monoliths onto an empty plain.

(Funnily enough, the way the original Thief engine worked was beginning with a fully solid universe which the level designers would carve air volumes out of to create the level. This was due to how the engine prioritised sound propagation. So Thief levels had to have positive outdoor spaces!)