Evaluation of historical museum interior lighting system using fully immersive virtual luminous environment

Saint Rocco Museum, a historical building in Venice, Italy is used as a case study to explore the performance of its' lighting system and visible light impact on viewing the large size art works. The transition from three-dimensional architectural rendering to the three-dimensional virtual luminance mapping and visualization within a virtual environment is described as an integrated optical method for its application toward preservation of the cultural heritage of the space. Lighting simulation programs represent color as RGB triplets in a device-dependent color space such as ITU-R BT709. Prerequisite for this is a 3D-model which can be created within this computer aided virtual environment. The onsite measured surface luminance, chromaticity and spectral data were used as input to an established real-time indirect illumination and a physically based algorithms to produce the best approximation for RGB to be used as an input to generate the image of the objects. Conversion of RGB to and from spectra has been a major undertaking in order to match the infinite number of spectra to create the same colors that were defined by RGB in the program. The ability to simulate light intensity, candle power and spectral power distributions provide opportunity to examine the impact of color inter-reflections on historical paintings. VR offers an effective technique to quantify the visible light impact on human visual performance under precisely controlled representation of light spectrum that could be experienced in 3D format in a virtual environment as well as historical visual archives. The system can easily be expanded to include other measurements and stimuli. © 2013 SPIE.