cloister_brass

The cloister's irrigation brass — polished where the weather kept it bright, green with verdigris wherever water has run, and streaked vertically below every joint. Triplanar off world space, with the streak field stretched down Y and tight around the girth so a pipe reads as a pipe rather than as noise.

patina and streak drive the oxidation, grime the soot that settles on horizontal faces, detail_scale the size of the whole pattern against the object. Exposes surface(); the metallic channel drops where the patina takes over, which is what stops green brass reading as green metal.