Reciprocal Shading for Mixed Reality

Martin Knecht, Christoph Traxler, Oliver Mattausch, Michael Wimmer
Reciprocal Shading for Mixed Reality
Computers & Graphics, 36(7):846-856, November 2012. [draft]

Information

Abstract

In this paper we present a novel plausible rendering method for mixed reality systems, which is useful for many real-life application scenarios, like architecture, product visualization or edutainment. To allow virtual objects to seamlessly blend into the real environment, the real lighting conditions and the mutual illumination effects between real and virtual objects must be considered, while maintaining interactive frame rates. The most important such effects are indirect illumination and shadows cast between real and virtual objects.

Our approach combines Instant Radiosity and Differential Rendering. In contrast to some previous solutions, we only need to render the scene once in order to find the mutual effects of virtual and real scenes. In addition, we avoid artifacts like double shadows or inconsistent color bleeding which appear in previous work. The dynamic real illumination is derived from the image stream of a fish-eye lens camera. The scene gets illuminated by virtual point lights, which use imperfect shadow maps to calculate visibility. A sufficiently fast scene reconstruction is done at run-time with Microsoft's Kinect sensor. Thus a time-consuming manual pre-modeling step of the real scene is not necessary. Our results show that the presented method highly improves the illusion in mixed-reality applications and significantly diminishes the artificial look of virtual objects superimposed onto real scenes.

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BibTeX

@article{knecht_martin_2012_RSMR,
  title =      "Reciprocal Shading for Mixed Reality",
  author =     "Martin Knecht and Christoph Traxler and Oliver Mattausch and
               Michael Wimmer",
  year =       "2012",
  abstract =   "In this paper we present a novel plausible rendering method
               for mixed reality systems, which is useful for many
               real-life application scenarios, like architecture, product
               visualization or edutainment. To allow virtual objects to
               seamlessly blend into the real environment, the real
               lighting conditions and the mutual illumination effects
               between real and virtual objects must be considered, while
               maintaining interactive frame rates. The most important such
               effects are indirect illumination and shadows cast between
               real and virtual objects.  Our approach combines Instant
               Radiosity and Differential Rendering. In contrast to some
               previous solutions, we only need to render the scene once in
               order to find the mutual effects of virtual and real scenes.
               In addition, we avoid artifacts like double shadows or
               inconsistent color bleeding which appear in previous work.
               The dynamic real illumination is derived from the image
               stream of a fish-eye lens camera. The scene gets illuminated
               by virtual point lights, which use imperfect shadow maps to
               calculate visibility. A sufficiently fast scene
               reconstruction is done at run-time with Microsoft's Kinect
               sensor. Thus a time-consuming manual pre-modeling step of
               the real scene is not necessary. Our results show that the
               presented method highly improves the illusion in
               mixed-reality applications and significantly diminishes the
               artificial look of virtual objects superimposed onto real
               scenes.",
  month =      nov,
  issn =       "0097-8493",
  journal =    "Computers & Graphics",
  number =     "7",
  volume =     "36",
  pages =      "846--856",
  keywords =   "Differential rendering, Reconstruction, Instant radiosity,
               Microsoft Kinect, Real-time global illumination, Mixed
               reality",
  URL =        "https://www.cg.tuwien.ac.at/research/publications/2012/knecht_martin_2012_RSMR/",
}