A Comparison Among Fast Visibility Algorithms Applied to Computational Electromagnetics
Keywords:
A Comparison Among Fast Visibility Algorithms Applied to Computational ElectromagneticsAbstract
This paper presents a set of fast algorithms developed for solving the visibility problem in large complex geometric scenarios. The implemented algorithms are: Binary Space Partitioning (BSP) –based on a binary tree structure- and three new ones: Trimming Method – facets which are partially occluded are trimmed –, Cone Method – a cone emerges from the point of view to discard shadowed facets – and Pyramid Method – a pyramid is used to eliminate non-lit patches – . All the proposed algorithms are tested on a pair of scenarios for determining the field of view of electromagnetic waves in order to calculate the corresponding induced currents on the surfaces. The scenarios consist of two electrically large spheres and two PEC plates respectively where the surfaces are meshed with a variable number of flat triangular patches. The first reflection contribution is calculated using Physical Optics (PO) for both cases. The results show that the computational time can be drastically reduced by assuming small percentage of error in the computed scattered fields.
Downloads
References
B. R. Dewey, Computer graphics for engineers.
USA: Harpercollins College Div., 1998.
J. D. Foley et al. , Computer Graphics. USA:
Addison-Wesley, 1992.
J. Bittner and P. Wonka , “Visibility in computer
graphics,” Environment and Planning B: Planning
and Design vol. 30, no. 5, pp. 729 – 755, 2003 .
M. F. Cátedra and J. P. Arriaga, Cell planning for
wireless communications . Boston: Artech House,
M. F. Cátedra, J. Pérez, F. S. de Adana, and O.
Gutiérrez, “Efficient ray-tracing techniques for three-
dimensional analyses of propagation in mobile
communications. Application to picocell and
microcell scenarios,” IEEE Antennas and
Propagation Magazine, vol. 40, no. 2, pp. 15-25,
A. Woo and J. Amanatides, “Voxel occlusion testing:
a shadow determination accelerator for ray tracing,”
Proceedings of Graphics interface '90 , pp. 213-220,
June 1990.
Y. Zhou and H. Ling, “On the multiplaten Z-buffer
algorithm for ray tracing in high frequency
electromagnetic scattering computations,”
Microwave and Optical Technology Letters, vol. 43,
pp. 298-301, 2004.
M. Reyer, T. Rick, and R. Mathar, “Graphics
hardware accelerated field strength prediction for
rural and urban environments,” Proceedings of the
Second European Conference on Antennas and
Propagation –EuCAP 2007, November 2007.
J. M. Rius, M. Ferrando, and L. Jofre, “GRECO
graphical electromagnetic computing for RCS
prediction in real time,” IEEE Antennas and
Propagation Magazine, vol. 35, no. 2, 1993.
MEANA, LAS-HERAS, MARTINEZ-LORENZO: COMPARISON AMONG FAST VISIBILITY ALGORITHMS
M. J. Inman and A. Z. Elsherbeni, “Programming
video cards for computational electromagnetics
applications,” IEEE Antennas and Propagation
Magazine, vol. 47, no. 6, 2005.
D. Shreiner, OpenGL reference manual: the official
reference document to OpenGL, Version 1.4.
London: Addison-Wesley, 2004.
H. Fuch, Z. M. Kedem, and B. F. Naylor, “On visible
surface generation by priori tree structures,” ACM
Siggraph Computer Graphics, vol. 14, no. 3, pp.
-133, 1980.
D. Gordon and S. Chen, “F ront-to-back display of
BSP trees,” IEEE Computer Graphics and
Applications, vol. 11, pp. 79-85, 1991.
C. W. Fu, T. T. Wong, et al., “Binary-space-
partitioned images for resolving image-based
visibility,” IEEE Transactions on Visualization and
Computer Graphics, vol. 10, no. 1, 2004.
F. Las-Heras, J. L. Ja mbrina, and E. Iguacel
“Different approximations for the double reflection
contribution to the RCS in a Physical Optics
algorithm,” Proceedings of the 7th European
Electromagnetic Structure Conference, pp. 11-14,
September, 1993.
C. A. Balanis, Engineering electromagnetics . New
York, USA: John Wiley and Sons, 1989.
A. M. Arias, J. O. Rubiños, I. Cuiñas, and A. G.
Pino, “Electromagnetic scattering of reflector
antennas by fast physical optics algorithms,” Recent
Res. Devel. Magnetics, no. 1, pp. 43-63, 2000
