Digital Archiving of the Spatial Experience of Cultural Heritage Sites with Ancient Lighting

Although adaptive reuse has made the preservation, restoration, and maintenance of architectural heritage sites possible due to the revenue generated by the new program, it has unfortunately induced unavoidable renovations that have altered the original design. Consequently, while the physical configuration of an architectural scene of a heritage site can be preserved and restored to mimic how it looked in the past, how to experience it as rendered with the original lighting design that might no longer be available. With the advancement of technologies related to High Dynamic Range Imaging, light models of various ancient illumination can be reconstructed and used as lighting sources for the virtual environment. Although ancient light sources can now be preserved in this digital form, this technique falls short of preserving the real visual perception of the significant canonical scene of cultural heritage with the originally intended lighting. This study proposes a conceptual framework for the digital archiving of the perceptual realism of the original lighting scheme of an architectural heritage site. The Taiwanese folk religion temples were included in a case study to demonstrate the framework; the study investigated how to identify the discrepancy between the scene-based lighting from the past and that of the current period due to adaptive reuse; further, this study determined the systematic method to select the canonical view that can best invoke the memorial spatial experience of the historical space; additionally, this study provides a case report of the restoration of past lighting with candles made with ancient recipes that were recovered from the field study, and the computational process of documenting scene-based lighting with related technologies using high dynamic range imaging. Finally, the researcher of this study conducted two perceptual experiments. The results of the first experiment demonstrated that the pattern of light and dark induced by the daylight falling into the courtyard plays a significant role regarding the viewers’ preference of the canonical scene of the traditional temple. The second experiment further demonstrated canonical views of three temples illuminated with artificial light, modern candlelight, and ancient candlelight, with ancient lighting being the preferred option of viewers.