Displacement Mapped Billboard Clouds

Information

• Publication Type: Technical Report
• Workgroup(s)/Project(s):
  • TreeLumination
• Date: January 2007
• Number: TR-186-2-07-01
• Keywords: rendering acceleration, billboard clouds, image-based rendering

Abstract

This paper introduces displacement mapped billboard clouds (DMBBC), a new image-based rendering primitive for the fast display of geometrically complex objects at medium to far distances. The representation is based on the well-known billboard cloud (BBC) technique, which represents an object as several textured rectangles in order to dramatically reduce its geometric complexity. Our new method uses boxes instead of rectangles, each box representing a volumetric part of the model. Rendering the contents of a box is done entirely on the GPU using ray casting. DMBBCs will often obviate the need to switch to full geometry for closer distances, which is especially helpful for scenes that are densely populated with complex objects, e.g. for vegetation scenes. We show several ways to store the volumetric information, with different tradeoffs between memory requirements and image quality. In addition we discuss techniques to accelerate the ray casting algorithm, and a way for smoothly switching between DMBBCs for medium distances and BBCs for far distances.

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BibTeX

@techreport{TR-186-2-07-01,
  title =      "Displacement Mapped Billboard Clouds",
  author =     "Stephan Mantler and Stefan Jeschke and Michael Wimmer",
  year =       "2007",
  abstract =   "This paper introduces displacement mapped billboard clouds
               (DMBBC), a new image-based rendering primitive for the fast
               display of geometrically complex objects at medium to far
               distances. The representation is based on the well-known
               billboard cloud (BBC) technique, which represents an object
               as several textured rectangles in order to dramatically
               reduce its geometric complexity. Our new method uses boxes
               instead of rectangles, each box representing a volumetric
               part of the model. Rendering the contents of a box is done
               entirely on the GPU using ray casting. DMBBCs will often
               obviate the need to switch to full geometry for closer
               distances, which is especially helpful for scenes that are
               densely populated with complex objects, e.g. for vegetation
               scenes. We show several ways to store the volumetric
               information, with different tradeoffs between memory
               requirements and image quality. In addition we discuss
               techniques to accelerate the ray casting algorithm, and a
               way for smoothly switching between DMBBCs for medium
               distances and BBCs for far distances.",
  month =      jan,
  number =     "TR-186-2-07-01",
  address =    "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria",
  institution = "Institute of Computer Graphics and Algorithms, Vienna
               University of Technology ",
  note =       "human contact: technical-report@cg.tuwien.ac.at",
  keywords =   "rendering acceleration, billboard clouds, image-based
               rendering",
  URL =        "https://www.cg.tuwien.ac.at/research/publications/2007/TR-186-2-07-01/",
}