The distinctive curving profile of East Asian roofs is made possible by a stepped truss system (13.8). (Western roofs, in contrast, are usually supported by a rigid triangular truss, as in the Greek pediment.) By varying the height of each level of the truss, builders could control the pitch and curve of the roof. Taste in roof styles varied over time and from region to region. Some roofs are steeply pitched and fall in a fancifully exaggerated curve, almost like a ski jump; others are gentler, with a subtle, barely noticeable curve.