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Jpeg Image (31 Ko)

Jpeg Image (24 Ko)

Author(s)

• Hideo Yamashita
  • Email : yama@eml.hiroshima-u.ac.jp

Institute(s)

• Hiroshima University, Electric Machinery Laboratory
  • Email : lab@eml.hiroshima-u.ac.jp
  • URL : http://www.eml.hiroshima-u.ac.jp/
  • Country : Japan

Film 1	Video QuickTime ->	(4.8 Mo)
	Jpeg Images ->	(12 Ko)

Film 2	Video QuickTime ->	(3.5 Mo)
	Jpeg Images ->	(11 Ko)

• Date : 05:90

• Category : Research

• Keys Words :

  • Wet Road Surfaces
  • Procedural Bump Mapping
  • Solar Penumbra
  • Streaks of Light
  • Diffraction Effects

• Theme(s) :

  • Architectural simulation
  • Light, shadows and reflects

Technical Information

1. A procedural bump mapping technique for modeling road surfaces and reflection model for rendering wet road surfaces and puddles.
2. A shadow model with penumbra effects taking into account the size of the sun.
3. A diffraction model of the pupil and eyelashes for rendering blooming effect and streaks of light.

• Hardware: Sequent S81, Silicon Graphics IRIS 4D
• Software: In house software

• Bibliography :

  1. E. Nakamae, K. Kaneda, T. Okamoto, T. Nishita: "A Lighting Model Aiming at Drive Simulators," Computer Graphics, Vol. 24, No. 4, pp. 395-404 (1990).
  2. S. Takita, K. Kaneda, T. Akinobu, H. Iriyama, E. Nakamae, T. Nishita: "A Simple Method for Rendering Penumbra Caused by Sunlight," The Visual Computer, Vol. 7, No. 5-6, pp. 259-268 (1991).
  3. E.Nakamae, "Lighting Model for Outdoor Scenes", Imagina Proceedings pp1_15 1991
  
  
  

• Abstract :

  [1] Many techniques for rendering natural objects such as the sea, terrains, and trees have been developed; they are indispensable for flight simulators. In this paper, techniques for rendering road surfaces under various conditions are discussed. Rendering road surfaces is quite useful for the evaluation of driving safety, and it will play an important part in the development of drive simulators. Light sources with high intensity often disturb drivers especially under wet road surface conditions. This paper proposes two models, a reflection model for road surfaces taking into account weather conditions, and a model on streaks of light taking into account both refraction and diffraction of light. Some examples demonstrate the possibility of applications for drive simulators in the future.

  [2] A simple rendering method for penumbrae caused by sunlight is proposed to create more realistic outdoor scenery. Only four points are used to define the penumbra area cast by a contour edge so that little strage is needed for penumbra area. Complex penumbrae caused by such objects as curtains can be rendered. Calculation of illumination in the shadows cast by natural objects, such as trees, mapped on a transparent virtual plane is available. In order to show the usefulness of the proposed method, some computer-generated images with penumbrae are compared with those without penumbrae.

  [3] The demand upon highly realistic visual simulation on outdoor scenes rapidly has been increasing. Four topics, recent works in the author's laboratory, concerning lighting models which play important parts in creating photorealistic outdoor scenes are discussed in this paper; modeling and rendering atmospheric conditions, penumbrae caused by the sunlight, wet road surfaces, and diffraction effects due to a diffraction grating, a pupil, and eyelashes.
  
  

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• Some internal links :

  Same Author

  Scenes at a Street Corner

  Rhapsody in Light & Blue