A Novel Ray-shooting Method to Render Night Urban Scenes - A Method based on Polar Diagrams

M. D. Robles-Ortega, J. R. Jiménez, L. Ortega

2014

Abstract

Illumination and shadows are essential to obtain realistic virtual environments. Nevertheless, large scenes like urban cities demand a huge amount of geometry that must somehow be structured or reduced in order to be manageable. In this paper we propose a novel real-time method to determine the shadowed and illuminated areas in large scenes, specially suitable for urban environments. Our approach uses the polar diagram as a tessellation plane, and a ray-casting process to obtain the visible areas. This solution derives the exact illuminated area with a high performance. Moreover, our approach is also used to determine the visible portion of the scene from a pedestrian viewpoint. As a result, we only have to render the visible part of the scene, which is considerably lower than the global scene.

References

  1. Argudo, O., Andújar, C., and Patow, G. (2012). Interactive rendering of urban models with global illumination. In Computer Graphics International, Bournemouth University, United Kingdom.
  2. Bittner, J., Wonka, P., and Wimmer, M. (2005). Fast exact from-region visibility in urban scenes. In Bala, K. and Dutr, P., editors, Rendering Techniques 2005 (Proceedings Eurographics Symposium on Rendering), pages 223-230. Eurographics, Eurographics Association.
  3. Buchholz, H. and Dollner, J. (2005). View-dependent rendering of multiresolution texture-atlases. In Visualization, 2005. VIS 05. IEEE, pages 215-222.
  4. Chin, N. and Feiner, S. (1989). Near real-time shadow generation using bsp trees. ACM SIGGRAPH Computer Graphics, 23(3):99-106.
  5. Cignoni, P., Di Benedetto, M., Ganovelli, F., Gobbetti, E., Marton, F., and Scopigno, R. (2007). Ray-casted blockmaps for large urban models visualization. Computer Graphics Forum, 26(3):405-413.
  6. Cohen-Or, D., Chrysanthou, Y., Silva, C., and Durand, F. (2003). A survey of visibility for walkthrough applications. Visualization and Computer Graphics, IEEE Transactions on, 9(3):412 - 431.
  7. Cohen-Or, D., Fibich, G., Halperin, D., and Zadicario, E. (1998). Conservative visibility and strong occlusion for viewpace partitioning of densely occluded scenes. In EUROGRAPHICS'98, volume 17, pages 243-253.
  8. Di Benedetto, M., Cignoni, P., Ganovelli, F., Gobbetti, E., Marton, F., and Scopigno, R. (2009). Interactive remote exploration of massive cityscapes. In The 10th International Symposium on Virtual Reality, Archaeology and Cultural Heritage VAST (2009), pages 9- 16. Eurographics.
  9. Dorsey, J. and Rushmeier, H. (2008). Light and materials in virtual cities. In ACM SIGGRAPH 2008 classes, SIGGRAPH 7808, pages 8:1-8:4, New York, NY, USA. ACM.
  10. Durand, F., Orti, R., Rivière, S., and Puech, C. (1996). Radiosity in flatland made visibly simple: using the visibility complex for lighting simulation of dynamic scenes in flatland. In Proceedings of the twelfth annual symposium on Computational geometry, SCG 7896, pages 511-512, New York, NY, USA. ACM.
  11. Eisemann, E., Schwarz, M., Assarsson, U., and Wimmer, M. (2011). Real Time Shadows. A K Peters/CRC Press.
  12. Germs, R. and Jansen, F. W. (2001). Geometric simplification for efficient occlusion culling in urban scenes. In Proc. of WSCG 2001, pages 291-298.
  13. Grima, C. I., Marquez, A., and Ortega, L. (2006). A new 2d tessellation for angle problems: The polar diagram. Computational Geometry. Theory and Applications, 34(2):58 - 74.
  14. Koldas, G., Isler, V., and Lau, R. W. H. (2007). Six degrees of freedom incremental occlusion horizon culling method for urban environments. In ADVANCES IN VISUAL COMPUTING, PT I, volume 4841 of Lecture Notes in Computer Science, pages 792-803.
  15. Musialski, P., Wonka, P., Aliaga, D. G., Wimmer, M., van Gool, L., and Purgathofer, W. (2013). A Survey of Urban Reconstruction. Computer Graphics Forum, Early View.
  16. Okabe, A., Boots, B., and Sugihara, K. (1992). Spatial Tessellations: Concepts and Applications of Voronoi Diagrams. John Wiley and Sons.
  17. Ortega, L. and Feito, F. (2005). Collision detection using polar diagrams. Computer & Graphics, 29(5):726- 737.
  18. Ortega, L. and Robles-Ortega, M. D. (2013). Applied mathematics & information sciences. ACM Trans. Graph., pages 1651-1669.
  19. Pocchiola, M. and Vegter, G. (1993). The visibility complex. In Proceedings of the ninth annual symposium on Computational geometry, SCG 7893, pages 328- 337, New York, NY, USA. ACM.
  20. Revanth, N. R. and Narayanan, P. J. (2012). Distributed massive model rendering. In Proceedings of the Eighth Indian Conference on Computer Vision, Graphics and Image Processing, ICVGIP 7812, pages 42:1-42:8. ACM.
  21. Robles-Ortega, M., Ortega, L., Coelho, A., Feito, F., and de Sousa, A. (2013). Automatic street surface modeling for web-based urban information systems. Journal of Urban Planning and Development, 139(1):40-48.
  22. Robles-Ortega, M. D., Ortega, L., and Feito, F. (2009). An exact occlusion culling method for navigation in virtual architectural environments. In Proceedings of the IV Iberoamerican Symposium in Computer Graphics, pages 23-32.
  23. Wonka, P. and Schmalstieg, D. (1999). Occluder shadows for fast walkthroughs of urban environments. Computer Graphics Forum, 18(3):51-60.
  24. Wonka, P., Wimmer, M., and Sillion, F. (2001). Instant visibility. Computer Graphics Forum, 20(3):C411+. 22nd Annual Conference of the European-Association-forComputer-Graphis, MANCHESTER, ENGLAND, SEP 04-07, 2001.
  25. Zara, J. (2006). Web-based historical city walks: advances and bottlenecks. Presence: Teleoper. Virtual Environ., 15(3):262-277.
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Paper Citation


in Harvard Style

Robles-Ortega M., Jiménez J. and Ortega L. (2014). A Novel Ray-shooting Method to Render Night Urban Scenes - A Method based on Polar Diagrams . In Proceedings of the 9th International Conference on Computer Graphics Theory and Applications - Volume 1: GRAPP, (VISIGRAPP 2014) ISBN 978-989-758-002-4, pages 53-63. DOI: 10.5220/0004718800530063


in Bibtex Style

@conference{grapp14,
author={M. D. Robles-Ortega and J. R. Jiménez and L. Ortega},
title={A Novel Ray-shooting Method to Render Night Urban Scenes - A Method based on Polar Diagrams},
booktitle={Proceedings of the 9th International Conference on Computer Graphics Theory and Applications - Volume 1: GRAPP, (VISIGRAPP 2014)},
year={2014},
pages={53-63},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0004718800530063},
isbn={978-989-758-002-4},
}


in EndNote Style

TY - CONF
JO - Proceedings of the 9th International Conference on Computer Graphics Theory and Applications - Volume 1: GRAPP, (VISIGRAPP 2014)
TI - A Novel Ray-shooting Method to Render Night Urban Scenes - A Method based on Polar Diagrams
SN - 978-989-758-002-4
AU - Robles-Ortega M.
AU - Jiménez J.
AU - Ortega L.
PY - 2014
SP - 53
EP - 63
DO - 10.5220/0004718800530063