Efficient Ray Tracing Through Aspheric Lenses and Imperfect Bokeh Synthesis

We present an efficient ray-tracing technique to render bokeh effects produced by parametric aspheric lenses. Contrary to conventional spherical lenses, aspheric lenses do generally not permit a simple closed-form solution of ray-surface intersections. We propose a numerical root-finding approach, which uses tight proxy surfaces to ensure a good initialization and convergence behavior. Additionally, we simulate mechanical imperfections resulting from the lens fabrication via a texture-based approach. Fractional Fourier transform and spectral dispersion add additional realism to the synthesized bokeh effect. Our approach is well-suited for execution on graphics processing units (GPUs) and we demonstrate complex defocus-blur and lens-flare effects.

@Article { JKLEL16,
  author       = "Joo, Hyuntae and Kwon, Soonhyeon and Lee, Sangmin and Eisemann, Elmar and Lee, Sungkil",
  title        = "Efficient Ray Tracing Through Aspheric Lenses and Imperfect Bokeh Synthesis",
  journal      = "Computer Graphics Forum",
  number       = "4",
  volume       = "35",
  pages        = "99-105",
  month        = "july",
  year         = "2016",
  url          = "http://graphics.tudelft.nl/Publications-new/2016/JKLEL16"
}