All right. Is this a term (or proverb) in traditional architecture in China? ), which is the form of the shape outline of the roof. "Starting from the mountain" means that the longitudinal angle of the roof is raised, and "falling vein" means that the second and third purlins on the roof on both sides of the horizontal slope are lowered by a certain height, forming a height difference.
It is better to understand the map in detail. . .
Ancient architecture emphasizes geomantic omen, but these two are only architectural techniques, so it is enough to talk about geomantic omen.