Rules · Roofs · Geometry · Theory
Classify the temple by the shape of its crown: square is nāgara, octagonal drāviḍa, round (or apsidal) vesara.
The treatises use the three names for shapes, not regions: a southern temple may have a “nāgara” (square) crown. Modern historians took the words over as names for the northern style, the southern style and the mixed style of the Deccan, which is convenient but not what the texts meant. The model lets you change the crown of the same vimana.
Set a vertical rod at the centre of the levelled site, draw a circle round it, mark where the tip of its shadow crosses the circle before and after noon, and join the two marks: that line runs east–west.
E–W = chord through the morning and afternoon shadow points; N–S ⟂ through its midpoint
The cord stretched along the diagonal of a rectangle produces as much area as the cords along its two sides together; use this to set out right angles and to make squares of any required area.
d² = a² + b²; e.g. cords of 3, 4, 5 or 5, 12, 13 units
Divide the square site into a grid of equal squares (padas), most often 8 × 8 = 64 or 9 × 9 = 81, and place every part of the building according to the grid.
64 padas (maṇḍūka) or 81 padas (paramaśāyika)
Imagine the vāstupuruṣa lying face down on the diagram with his head in the north-east and his feet in the south-west, held down by the gods who occupy the padas; do not place walls, pillars or doors on his vital points.
Read the diagram from the centre outward: Brahmā at the heart, then a ring of the gods, a ring of human concerns, and on the outside the lesser spirits; the holiest function goes at the centre and the most worldly at the edge.
81 padas = 9 (Brahmā) + 16 + 24 + 32
Break each face of the square sanctum into projections (rathas), three, five, seven or more, that step forward towards the central one, and carry them up unbroken through the wall and the tower.
tri-ratha 3 · pancha-ratha 5 · sapta-ratha 7 projections per face
Cite this page Chris Paton, “Nāgara, drāviḍa, vesara”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/three-shapes. Text, drawings and models licensed under CC BY-NC 4.0.