@InProceedings{KellerWald:2000:ISTPM,
     author =       "Alexander Keller and Ingo Wald",
     title =        "{Efficient} {Importance} {Sampling} {Techniques} for the {Photon} {Map}",
     year =         "2000",
     month =        November,
     booktitle =    "Vision Modelling and Visualization 2000",
     pages =        "271--279",
     address =      "Saarbruecken, Germany",
     keywords =     "importance sampling, photon map", 
     pdf_link =     "http://graphics.cs.uni-sb.de/~wald/Publications/Papers/PMapImportanceSampling.pdf",
     abstract = {In Global Illumination computations the photon map is a powerful tool for approximating the irradiance, which is stored independent from scene geometry. By presenting a new algorithm, which uses novel importance sampling techniques, we improve the memory footprint fo the photon map, simplyfy the caustic generation, and allow for a much fsater sampling of direct illumination in complicated models as they arise in a production environment.},
   }