What is Feng Shui? Does feng shui have to be useful?

Take "facing the mountain, facing the water and facing the sun" as the best natural orientation. Appropriate "low in front and high in back" is the best residential terrain, emphasizing the natural orientation of "water inlet" (including water inlet and water outlet) and "air outlet" (including doors and windows) of residential buildings, and advocating that the height of room space and the darkness of indoor lighting should be appropriate. These environmental factors are closely related to people's physical and mental health. Otherwise, no matter how strong a person is, if he builds his house in a place with natural hazards, or builds his room into an artificial environment with poor lighting, ventilation, temperature and humidity, he will also get sick. From the perspective of environmental architecture, these are all scientific and worthy of serious study and reference. Judging from the cultural environment and orientation, the theory of Feng Shui is based on the Yi-ology culture such as Hetu, Luoshu, Bagua and Wuxing. Through metaphor and symbolic means such as architectural layout, spatial division, orientation adjustment, color application and pattern selection, the pursuit of harmonious environment between body and mind is realized.