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Producing Visually Accurate Simulations Using Free Rendering Software

Case Study: Adapting Ray-Tracing Software for Physically Accurate Simulation

This research study demonstrates a new way to create physically accurate visual stimuli for the study of human visual perception using free software developed for lighting design.


To establish if RADIANCE, freely licensed ray-tracing software, could be used to produce stimuli for the study of human perception.


EPSRC (Engineering and Physical Sciences Research Council) grant.


RADIANCE is a physically based, freely available, and commonly used rendering software. We modified the program to allow for spectral rendering and validated the calculation accuracy by comparing simulation results with measurements from real scenes with particular emphasis on colour reproduction.


At the time of publication there is no better simulation alternative for achieving physical realism (i.e., the simulation result providing the same visual stimulation as a real scene) than by combining our spectral rendering method with RADIANCE.


  • Ruppertsberg, A, and Bloj, M (2006) "Rendering complex scenes for psychophysics using RADIANCE: How accurate can you get?", J. Opt. Soc. Am. A23, 759-768
  • Ruppertsberg, A.I. and Bloj, M. (2008), "Creating physically accurate visual stimuli for free: Spectral rendering with RADIANCE", Behavior Research Methods40, 304-308