Merging Ray Tracing and Rasterization in Mixed Reality

Information

• Publication Type: Bachelor Thesis
• Workgroup(s)/Project(s):
  • Reciprocal Shading for Mixed Reality
• Date: November 2012
• Date (Start): 1. March 2012
• Date (End): 30. November 2012
• Matrikelnummer: 0926881
• First Supervisor:
  • Michael Wimmer
  • Martin Knecht
• Keywords: Refraction, OptiX, Augmented Reality, Reflection

Abstract

In mixed reality, virtual objects are inserted into a video stream of a real environment. This technique can be used for many applications including marketing, simulations and cultural heritage. Therefore it is important that the images look plausible. Many applications also have real time constraints. With traditional rasterization it is difficult to create realistic reflections and refractions. In ray tracing on the other hand this is a trivial task, but rendering is slow. The solution described in this work uses the graphics card for speeding up ray tracing. Additionally it employs a rasterizer for diffuse surfaces and only traces rays if there is a reflective or refractive surface visible. This works by creating a ray tracing mask using the fast rasterizer in a first step. It holds true for reflective or refractive surfaces and false otherwise. Then all diffuse objects are drawn using the rasterizer. Finally rays are traced on each pixel which is masked as reflective or refractive surface by the ray tracing mask. These rays produce secondary rays which can hit a diffuse surface eventually. In this case the ray tracer takes over the shading. Results show, that our hybrid rendering method allows high quality reflections and refractions while still having interactive frame rates in mixed reality scenarios.

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BibTeX

@bachelorsthesis{celarek_adam-2012-rrmro,
  title =      "Merging Ray Tracing and Rasterization in Mixed Reality",
  author =     "Adam Celarek",
  year =       "2012",
  abstract =   "In mixed reality, virtual objects are inserted into a video
               stream of a real environment. This technique can be used for
               many applications including marketing, simulations and
               cultural heritage. Therefore it is important that the images
               look plausible. Many applications also have real time
               constraints. With traditional rasterization it is difficult
               to create realistic reflections and refractions. In ray
               tracing on the other hand this is a trivial task, but
               rendering is slow. The solution described in this work uses
               the graphics card for speeding up ray tracing. Additionally
               it employs a rasterizer for diffuse surfaces and only traces
               rays if there is a reflective or refractive surface visible.
               This works by creating a ray tracing mask using the fast
               rasterizer in a first step. It holds true for reflective or
               refractive surfaces and false otherwise. Then all diffuse
               objects are drawn using the rasterizer. Finally rays are
               traced on each pixel which is masked as reflective or
               refractive surface by the ray tracing mask. These rays
               produce secondary rays which can hit a diffuse surface
               eventually. In this case the ray tracer takes over the
               shading.  Results show, that our hybrid rendering method
               allows high quality reflections and refractions while still
               having interactive frame rates in mixed reality scenarios.",
  month =      nov,
  address =    "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria",
  school =     "Institute of Computer Graphics and Algorithms, Vienna
               University of Technology ",
  keywords =   "Refraction, OptiX, Augmented Reality, Reflection",
  URL =        "https://www.cg.tuwien.ac.at/research/publications/2012/celarek_adam-2012-rrmro/",
}