'Ray' motif dome expansion

'Ray' motif dome expansion

The 'ray' motif of muqarnas dome expansion is perhaps the simplest and most symmetrical method. There are two 'rays' as seen at the top of the dome.

The longest 'ray' starts at the top center and goes to the outer bottom. It is made up of the eight odd-numbered muqarnas tiles: 1, 3, 5, 7, 9, 11, 13 & 15. The long 'rays' are moved straight down and away from the center so that the top point of the next layer is coincident with the lowest, outermost point of the long 'ray' of the previous layer.

The short 'rays' are made of the even-numbered muqarnas tiles: 2, 4, 6, 8, 10, 12 & 14. They are a little trickier when placing for expansion. They do not start at the top and so it is not simply a matter of 'kissing' top to bottom points. They must be placed at the same relative position from the previous layers' short 'rays' as they are from the top in the simple dome. Confusing? Only a little.