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LightSketch: A sketch-modeling program for lighting analysis
    Dan Glaser, Jan Voung, Ling Xiao, Bonnie Tai,
    M. Susan Ubbelohde , John Canny, Ellen Yi-Luen Do
    CAAD Futures p 371-382 2003
    abstract:
    This paper presents a flexible, yet powerful lighting analysis tool, LightSketch.
    LightSketch is a sketch-based modelling program for lighting analysis. It allows the user
    to draw both architectural and lighting related symbols which are converted into a 3D
    model for lighting visualization. It is motivated by examining the strengths and
    limitations of current lighting design practices. Its use is illustrated with design
    scenarios.