Subscribe
Issue No.01 - January (2011 vol.17)
pp: 51-63
Tze-Yiu Ho , City University of Hong Kong, Hong Kong
Liang Wan , City University of Hong Kong, Hong Kong
Chi-Sing Leung , City University of Hong Kong, Hong Kong
Ping-Man Lam , City University of Hong Kong, Hong Kong
Tien-Tsin Wong , The Chinese University of Hong Kong, Hong Kong
ABSTRACT
Cube mapping is widely used in many graphics applications due to the availability of hardware support. However, it does not sample the spherical surface evenly. Recently, a uniform spherical mapping, isocube mapping, was proposed. It exploits the six-face structure used in cube mapping and samples the spherical surface evenly. Unfortunately, some texels in isocube mapping are not rectilinear. This nonrectilinear property may degrade the filtering quality. This paper proposes a novel spherical mapping, namely unicube mapping. It has the advantages of cube mapping (exploitation of hardware and rectilinear structure) and isocube mapping (evenly sampling pattern). In the implementation, unicube mapping uses a simple function to modify the lookup vector before the conventional cube map lookup process. Hence, unicube mapping fully exploits the cube map hardware for real-time filtering and lookup. More importantly, its rectilinear partition structure allows a direct and real-time acquisition of the texture environment. This property facilitates dynamic environment mapping in a real time manner.
INDEX TERMS
Unicube mapping, dynamic environment mapping, equal-area strip, filtering quality.
CITATION
Tze-Yiu Ho, Liang Wan, Chi-Sing Leung, Ping-Man Lam, Tien-Tsin Wong, "Unicube for Dynamic Environment Mapping", IEEE Transactions on Visualization & Computer Graphics, vol.17, no. 1, pp. 51-63, January 2011, doi:10.1109/TVCG.2009.205
REFERENCES
 [1] N. Greene, "Environment Mapping and Other Applications of World Projections," IEEE Computer Graphics and Applications, vol. 6, no. 11, pp. 21-29, Nov. 1986. [2] J. Kautz and M.D. McCool, "Approximation of Glossy Reflection with Prefiltered Environment Maps," Proc. Graphics Interface, pp. 119-126, 2000. [3] M. Ashikhmin and A. Ghosh, "Simple Blurry Reflections with Environment Maps," J. Graphics Tools, vol. 7, no. 4, pp. 3-8, 2002. [4] G. King and W. Newhall, "Efficient Omnidirectional Shadow Maps," ${\rm ShaderX}^3$ : Advanced Rendering with DirectX and OpenGL, W. Engel, ed., pp. 435-448, Charles River Media, 2005. [5] D. Voorhies and J. Foran, "Reflection Vector Shading Hardware," Proc. ACM SIGGRAPH '94, pp. 163-166, 1994. [6] P. Shirley and K. Chiu, "A Low Distortion Map between Disk and Square," J. Graphics Tools, vol. 2, no. 3, pp. 45-52, 1997. [7] K.M. Gorski, B.D. Wandelt, E. Hivon, F.K. Hansen, and A.J. Banday, "The HEALPix Primer," technical report, Theoretical Astrophysics Center (TAC), astro-ph/9905275, Feb. 2003. [8] L. Wan, T.-T. Wong, and C.-S. Leung, "Isocube: Exploiting the Cubemap Hardware," IEEE Trans. Visualization and Computer Graphics, vol. 13, no. 4, pp. 720-731, July/Aug. 2007. [9] OpenGL_ARB, OpenGL Specification, Version 1.1, 1995. [10] W. Heidrich and H.-P. Seidel, "View-Independent Environment Maps," Proc. Graphics Hardware Conf., pp. 39-45, 1998. [11] N. Greene, "Environment Mapping and Other Applications of World Projections," IEEE Computer Graphics and Applications, vol. 6, no. 11, pp. 21-29, Nov. 1986. [12] J.L. Mitchell, "Motion Blurring Environment Maps," ${\rm ShaderX}^4$ , W. Engel, ed., pp. 263-268, Charles River Media, 2006. [13] T. Fortes, "Tetrahedron Environment Maps," MS thesis, Chalmers Univ. of Tech nology, 2000. [14] I. Takashi, "Dynamic Global Illumination Using Tetrahedron Environment Mapping," ${\rm ShaderX}^4$ , W. Engel, ed., pp. 157-169, Charles River Media, 2006. [15] T. Engelhardt and C. Dachsbacher, "Octahedron Environment Maps," Proc. Vision, Modelling and Visualization Conf., 2008. [16] E. Praun and H. Hoppe, "Spherical Parameterization and Remeshing," Proc. ACM SIGGRAPH '03, vol. 22, no. 3, pp. 340-349, 2003. [17] T.-T. Wong, L. Wan, C.-S. Leung, and P.-M. Lam, "Real-Time Environment Mapping with Equal Solid-Angle Spherical Quad-Map," Shader ${\rm X}^4$ : Lighting & Rendering, W. Engel, ed., Charles River Media, 2006. [18] J.-D. Gascuel, N. Holzschuch, G. Fournier, and B. Péroche, "Fast Non-Linear Projections Using Graphics Hardware," Proc. Symp. Interactive 3D Graphics and Games (SI3D '08), pp. 107-114, 2008. [19] J.J. Cui and W. Freeden, "Equidistribution on the Sphere," SIAM J. Scientific Computing, vol. 18, no. 2, pp. 595-609, 1997. [20] W.M. Smart, Text-Book on Spherical Astronomy, sixth ed. Cambridge Univ. Press, 1960.