(Vaastu - physical environment and Shastra- knowledge/ text/ principles. The 't' in both the words is dental. Also spelled Vastu) is one of the traditional Hindu canons of town planning and architecture. These canons are codified in texts such as Manasara Silpa Shastra (by Manasara), Mayamatam (by Maya), Viswakarma Vaastushastra (by Viswakarma), Samarangana Sutradara (by Raja Bhoja), Aparajita Praccha (by Viswakarma's son Aparajita) and Silparatna. Other treatises such as Agni Purana and works by Kautilya and Sukracharya are not popular even though they preceded the previously mentioned documents. Distinction of style exists due to each documents place of origin. Mayamata and Mansara Silpa Shastra are considered Dravidian because they are from south India whereas Viswaskarama Vaastu Shastra is considered Aryan due to its north Indian origin. Vaastu Shastra deals with various aspects of designing and building living environments that are in harmony with the physical and metaphysical forces/ energies of the cosmos such as the gravitational, electromagnetic and supernatural. Building practices based on limited interpretations of these principles are still sustained in specific areas of India. Though Vastu is conceptually similar to Feng Shui in that it also tries to harmonize the flow of energy (Also called Life-force, and Prana in Sanskrit, similar to Chi in Chinese) through the house, it differs in the details, such as the exact directions in which various objects, rooms, materials etc are to be placed.