Parameterizing the Geometry and Visualizing the Lighting Method of Byzantine Church Domes

This paper introduces a computer-based tool for the analysis of the geometry and the daylighting of Byzantine church domes to facilitate experimentation with a number of cases before any fieldwork is undertaken. Starting with a geometric derivation of the relationship between dome parameters, the digital tool builds an interactive three-dimensional model of a Byzantine church dome. The model allows the user to input the properties of the dome, the drum, any windows, and the slope of their sills. The model allows the user to define the dome using three different curvatures since such a case was identified in a Mistras church. A custom ray-tracing algorithm visualizes the path of light rays falling on the windowsills and their reflections within the dome. It was found that several parameters are interrelated and that an optimal set of proportions must be established to achieve the expected behavior of light within the dome.