Reflective and Refractive Objects for Mixed Reality

Martin Knecht, Christoph Traxler, Christoph Winklhofer, Michael Wimmer
Reflective and Refractive Objects for Mixed Reality
IEEE Transactions on Visualization and Computer Graphics (Proceedings of IEEE VR 2013), 19(4):576-582, March 2013. [Slides]

Information

Abstract

In this paper, we present a novel rendering method which integrates reflective or refractive objects into a differential instant radiosity (DIR) framework usable for mixed-reality (MR) applications. This kind of objects are very special from the light interaction point of view, as they reflect and refract incident rays. Therefore they may cause high-frequency lighting effects known as caustics. Using instant-radiosity (IR) methods to approximate these high-frequency lighting effects would require a large amount of virtual point lights (VPLs) and is therefore not desirable due to real-time constraints. Instead, our approach combines differential instant radiosity with three other methods. One method handles more accurate reflections compared to simple cubemaps by using impostors. Another method is able to calculate two refractions in real-time, and the third method uses small quads to create caustic effects. Our proposed method replaces parts in light paths that belong to reflective or refractive objects using these three methods and thus tightly integrates into DIR. In contrast to previous methods which introduce reflective or refractive objects into MR scenarios, our method produces caustics that also emit additional indirect light. The method runs at real-time frame rates, and the results show that reflective and refractive objects with caustics improve the overall impression for MR scenarios.

Additional Files and Images

Additional images and videos

Additional files

Slides: Slides Slides: Slides

Weblinks

BibTeX

@article{knecht_martin_2013_ReflRefrObjsMR,
  title =      "Reflective and Refractive Objects for Mixed Reality",
  author =     "Martin Knecht and Christoph Traxler and Christoph Winklhofer
               and Michael Wimmer",
  year =       "2013",
  abstract =   "In this paper, we present a novel rendering method which
               integrates reflective or refractive objects into a
               differential instant radiosity (DIR) framework usable for
               mixed-reality (MR) applications. This kind of objects are
               very special from the light interaction point of view, as
               they reflect and refract incident rays. Therefore they may
               cause high-frequency lighting effects known as caustics.
               Using instant-radiosity (IR) methods to approximate these
               high-frequency lighting effects would require a large amount
               of virtual point lights (VPLs) and is therefore not
               desirable due to real-time constraints. Instead, our
               approach combines differential instant radiosity with three
               other methods. One method handles more accurate reflections
               compared to simple cubemaps by using impostors. Another
               method is able to calculate two refractions in real-time,
               and the third method uses small quads to create caustic
               effects. Our proposed method replaces parts in light paths
               that belong to reflective or refractive objects using these
               three methods and thus tightly integrates into DIR. In
               contrast to previous methods which introduce reflective or
               refractive objects into MR scenarios, our method produces
               caustics that also emit additional indirect light. The
               method runs at real-time frame rates, and the results show
               that reflective and refractive objects with caustics improve
               the overall impression for MR scenarios.",
  month =      mar,
  issn =       "1077-2626",
  journal =    "IEEE Transactions on Visualization and Computer Graphics
               (Proceedings of IEEE VR 2013)",
  number =     "4",
  volume =     "19",
  pages =      "576--582",
  keywords =   "Mixed Reality, Caustics, Reflections, Refractions",
  URL =        "https://www.cg.tuwien.ac.at/research/publications/2013/knecht_martin_2013_ReflRefrObjsMR/",
}