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    Recreating Early Islamic Glass Lamp Lighting
    (The Eurographics Association, 2009) Jr., Joseph T. Kider; Fletcher, Rebecca L.; Yu, Nancy; Holod, Renata; Chalmers, Alan; Badler, Norman I.; Kurt Debattista and Cinzia Perlingieri and Denis Pitzalis and Sandro Spina
    Early Islamic light sources are not simple, static, uniform points, and the fixtures themselves are often combinations of glass, water, fuel and flame. Various physically based renderers such as Radiance are widely used for modeling ancient architectural scenes; however they rarely capture the true ambiance of the environment due to subtle lighting effects. Specifically, these renderers often fail to correctly model complex caustics produced by glass fixtures, water level, and fuel sources.While the original fixtures of the 8th through 10th century Mosque of Cordoba in Spain have not survived, we have applied information gathered from earlier and contemporary sites and artifacts, including those from Byzantium, to assume that it was illuminated by either single jar lamps or supported by polycandela that cast unique downward caustic lighting patterns which helped individuals to navigate and to read. To re-synthesize such lighting, we gathered experimental archaeological data and investigated and validated how various water levels and glass fixture shapes, likely used during early Islamic times, changed the overall light patterns and downward caustics. In this paper, we propose a technique called Caustic Cones, a novel data-driven method to "shape" the light emanating from the lamps to better recreate the downward lighting without resorting to computationally expensive photon mapping renderers.Additionally, we demonstrate on a rendering of the Mosque of Cordoba how our approach greatly benefits archaeologists and architectural historians by providing a more authentic visual simulation of early Islamic glass lamp lighting.
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    The Virtual Reconstruction and Daylight Illumination of the Panagia Angeloktisti
    (The Eurographics Association, 2009) Happa, Jassim; Artusi, Alessandro; Dubla, Piotr; Bashford-Rogers, Tom; Debattista, Kurt; Hulusic, Vedad; Chalmers, Alan; Kurt Debattista and Cinzia Perlingieri and Denis Pitzalis and Sandro Spina
    High-fidelity virtual reconstructions can be used as accurate 3D representations of historical environments. After modelling the site to high precision, physically-based and historically correct light models must be implemented to complete an authentic visualisation. Sunlight has a major visual impact on a site; from directly lit areas to sections in deep shadow. The scene illumination also changes substantially at different times of the day. In this paper we present a virtual reconstruction of the Panagia Angeloktisti; a Byzantine church on Cyprus. We investigate lighting simulations of the church at different times of the day, making use of Image-Based Lighting, using High Dynamic Range Environment Maps of photographs and interpolated spectrophotometer data collected on site. Furthermore, the paper also explores the benefits and disadvantages of employing unbiased rendering methods such as Path Tracing and Metropolis Light Transport for cultural heritage applications.