The sacred writings are arranged in four groups: (1) the Vedas; (2) the Upavedas or Supplementary Vedas; (3) the Vedarigas or Limbs of the Vedas; and (4) the Upangas or Supplementary Arigas. The four Upavedas are: (1) Ayurveda, or the science of life and medicine, derived from the Rig Veda; (2) Gandharva Veda, or the science of music, derived from the Sama Veda; (3) Dhanur Veda, or military science, derived from the Yajur Veda; and (4) Shilpa or Sthapatya Veda, or the mechanical arts and architecture, derived from the Atharva Veda.
The text-book of Vastu Shastra are records of oral traditions which go back into an undefined past. The Brihat Samhita, for instance, compiled by Varahamihira in the middle of the sixth century A.D., is based on the authority of Master Architects Maya, Visvakarma, Gargya and Manu. It is the earliest datable source on Vastu Shastra.
The Visvakarmanvaya-pradipika explains that creation is another name for Shilpa, and the origin of Shilpa or 'form' is Brahma, Tvastra and Prajapati put together, called Visvakarma. Visvakarma is Prajapati as the universal constructive principle. He is called Visvakarma because he created the activity of everything. The five heads of Visvakarma are Sadyojata, Vamadeva, Aghora, Tatpurusa an Isana, representing East (Rig Veda), South (Yajur Veda), West (Sama Veda), North (Atharva Veda) and North-East (Pranava Veda), respectively. The fifth direction North-East arose from the middle of these four heads. While destroying he is called Rudra, while protecting Lord Vishnu and while creating he is known as Lord Brahma.
Vastu Shastra, in its fullest exposition, belongs to aesthetics. Three prominent schools of philosophy had deep theoretical impact on the evolution of philosophical postulates in Indian aesthetics, viz. Rasabrahma-veda, Nadabrahma-veda and Vastubrahma-veda.
The Atharvaveda, however, refers to six regions or lokas and their six respective guardians - Lord Agni (South), Indra (East), Lord Varuna (West), Soma (North), Vishnu (Fixed quarter) and Brihaspati (Upward quarter). In the Krishna Yajur Veda (Taittiriya Samhita) the same six regions and their respective regents are mentioned, but Vishnu is replaced by Lord Yama.
The Manusmrti explains the eight lokapalas thus: Soma (Chandra), Agni Arka (Surya), Anila (Vayu), Indra, Vispati (Kubera), Appati (Varuna) and Yama. In this list Surya and Soma have been enumerated in place of Nirrti and Isana of the later Puranic texts. The Gobhila Grhyasutra, while describing the rites connected with building of a house, states that offerings should be made to the regents of ten regions (disas), namely, Indra (East), Vayu (South-East), Yama (South), Pitr (South-West), Varuna (West), Maharaja (North-West), Soma (North), Mahendra (North-East), Vasuki (Nadir) and Brahma (Zenith).
The Buddhist texts speak of only four lokapalas: Dhrtarastra (East), Vidudhaka (South), Virupaksa (West) and Vaisravana (North). The Matsya Purana further says that a house having only two rooms on the West is very auspicious, and that with those on the South is inauspicious.
The Rig Veda postulates only water as the primordial element or matter, from which the other five elements of later philosophy evolve. Varuna is the upholder of physical and moral order. By his power of Maya he sends forth dawn and makes the Sun (who is also described as his eye) traverse the sky. Varuna, with Mitra, is most frequently invoked as the bestower of rain. Dual divinities like Mitra-Varuna and Dyava-Prthivi are a special characteristic of the Rig Veda. The release of waters and the breaking forth of dawn or emergence of light are described as simultaneous events originating from the same source. These waters are described as moved upwards by Indra when set free for movement after killing of the demon Vritra. Their onward movement is, as described in the Rig Veda, where seven rivers are said to flow into the jaws of Varuna as into a surging abyss or ocean. The universe is said to have consisted of nothing but undifferentiated waters in the beginning. This cosmic circulation of celestial waters is also stated in the Zend Avesta, the Greek and Egyptian mythologies.
The Vastu Shastra Upanishad is more fundamental than the other known texts. It is a profound study of the principles of origin of the 'how' and 'why' of form figuration and of its ultimate necessity and purpose. Dealing exclusively with the composition and layout of sculpture, it contains an esoteric doctrine, in which the production of Shilpa is considered as a sacrificial act. In sage Pippalada's conception, the language of form is equivalent to the spoken or written word or 'Vak' giving expression to a vision of divine truth.