The feathers of a bird's wing underlap each other.

鸟翅上羽毛是部分相互重叠。

Adjust the Z intensity of the standard brush to 28 now and draw a new set of feathers through the FeatherSet.01 subtool until they appear to overlap (or underlap) the feathers of FeatherSet.01.

standard笔刷深度28，出一套新羽毛，使其部分浮现于第一个羽毛子物体之上。