Rose Window
Mullions out to the rim, and at every ring a course of foils sized to close the gap exactly.
About this pattern
Gothic plate and bar tracery · Chartres, Notre-Dame
Bar tracery works outward: each ring carries a whole number of circles, and their radius is not chosen but forced: it is whatever makes neighbours touch at that distance from the centre. Doubling the count on the next ring out keeps the stone the same thickness all the way to the rim, which is the constraint the Gothic masons were actually solving and the reason these windows look designed rather than decorated.