Omni-directional Relief Impostors
Abstract
Relief impostors have been proposed as a compact and high-quality
representation for high-frequency detail in 3D models. In this paper we propose
an algorithm to represent a complex object through the combination of a reduced
set of relief maps. These relief maps can be rendered with very few artifacts
and no apparent deformation from any view direction. We present an efficient
algorithm to optimize the set of viewing planes supporting the relief maps, and
an image-space metric to select a sufficient subset of relief maps for each
view direction. Selected maps (typically three) are rendered based on the
well-known ray-height-field intersection algorithm implemented on the GPU. We
discuss several strategies to merge overlapping relief maps while minimizing
sampling artifacts and to reduce extra texture requirements. We show that our
representation can maintain the geometry and the silhouette of a large class of
complex shapes with no limit in the viewing direction. Since the rendering cost
is output sensitive, our representation can be used to build a hierarchical
model of a 3D scene. Omni-directional relief impostors are described in the
following paper:
C. Andújar, J. Boo, P. Brunet, M. Fairén, I. Navazo, P. Vázquez, Ŕ. Vinacua.
Omni-directional Relief Impostors, in Proc. EUROGRAPHICS'07.
Movies
These are some movies showing our results (XviD codec required).
Movie: Armadillo - 3 best impostors (shifted and scaled for clarity) (860KB)
Movie: Armadillo - results using 3 relief maps on average (864KB)
Movie: EG dragon - results using 3 relief maps on average (374KB)
Movie: Bunny - results using 3 relief maps on average (368KB)
Movie: Navigation with Hierarchical ORIs (820KB)
Movie: Max Planck model - using 3 relief maps on average
Movie: Lucy model - using 4 relief maps on average
Movie: Dinosaur - using 3 relief maps on average
Model credits
Stanford 3D Scanning Repository (Armadillo, Bunny and Lucy)Cyberware (Dinosaur and horse)
Clemson University (Skeleton Hand)
MPI (Max Planck bust)
Shader source code
Source code of the shader (May 2007 version) can be downloaded here.C. Andújar, J. Boo, P. Brunet, M. Fairén, I. Navazo, P. Vázquez, Ŕ. Vinacua, 2006.