# Two-Dimensional Shape Analysis of Complex Geometry Based on Photogrammetric Models of Iconostases
## 3 Materials
### Iconostases' Historic Background  
Iconostases are unique and one of the most valuable art and architectural elements of the Christian Orthodox church cultural heritage especially considering they hold many icons, usually painted by prominent artists. They initially evolved from a very low altar screen called Byzantine templon [3; 4; 5; 6]. Their development into a multi-tier and richly decorated vertical frame, composed of religious paintings, is related to the late 14 th and 15 th century [6]. This form of altar partition crossed from Russia to Mount Athos and from there, it spread to Greece and the Balkans during Turkish occupation [3; 6]. The modern iconostasis evolved during the 16 th century [3]. By the 18 th century, the multi-tier iconostases were considered the most decorative elements of the Christian Orthodox churches, distinctive by their artistic, architectural, visual, and theological significance. The iconostasis' wooden framework and ornamental carvings were made by skilled craftsmen, while the icons were painted by the most influential artists of the particular period. The architectural and visual characteristics of iconostases are mostly related to the period of church origin [4] and the artistic movement current at the time of its development. An iconostasis' origin is very often related to the period of church construction, although there are examples of subsequent installation of iconostases. The design of the iconostasis' general shape is based on symmetry, while its dimensions are mainly dictated by the width and height of the altar space of the church in which it is situated. There is also a relatively stable arrangement of icons in the rows of the multi-story iconostasis. The important elements of an iconostasis are icons placed into specifically designed frames. Icons are supported by richly carved frames and a whole structure is usually made of marbled and/or gilded wood construction. The main constructive elements of the iconostases present columns placed on the pedestals (basis) and moldings which are contained on every iconostasis tier. The frames that hold icons are particularly carved into ornaments that represent various motifs related to an artistic style or symbol from the Bible. The number of tiers usually depends on a church's height, while the most developed iconostases can consist of five tiers. The placement of icons on multi-tier iconostases usually follows the following convention (Figure 1):  
* The bottom tier always contains the middle doors, called Royal doors and the North and South doors, each with framed icons. * On the right side of the Royal Doors is an icon of [PERSON] and on the left side is an icon of the [PERSON]. * The rest of the tiers usually contain one central icon and the twelve icons expanded to either side of it, often depicting either the Twelve Apostles, the Prophets, or The Great Feasts, while the last tier icons are arranged around the cross. Apart from the well-known facts of the iconostasis' structure design and symbolical meanings of the particular elements, there were no uniform shape characteristics in the design of the iconostasis' ornamental elements in relation to the style to which it belongs to. Besides the theological symbolism, the design of the carved ornament which holds the icons in each tier and other structural elements were often left to the craftsman's own inclination [4]. In addition, woodcarving and decorative plasterworks were very often associated with unknown masters. In Serbia, the iconostasis design differed during the two art movements, the Baroque (beginning of the 18 th century until 1790) and the Classicism (1790-1850) period, especially pronounced on the territory of the former Metropolitan of Karlovci in the Vojvodina region [7]. The stylistic characteristics of Classicism are reflected in the regularity, symmetry, and tendency towards orthogonal forms, in contrast to the characteristics of Baroque in which elliptical and asymmetrical shapes predominated.