Ray tracing volume densities

ABSTRACT

This paper presents new algorithms to trace objects represented by densities within a volume grid, e.g. clouds, fog, flames, dust, particle systems. We develop the light scattering equations, discuss previous methods of solution, and present a new approximate solution to the full three-dimensional radiative scattering problem suitable for use in computer graphics. Additionally we review dynamical models for clouds used to make an animated movie.

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INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.7 Three-Dimensional Graphics and Realism
          Subjects: Raytracing

Additional Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.3 Picture/Image Generation
      I.3.5 Computational Geometry and Object Modeling

General Terms:
Algorithms, Design

Keywords:
Clouds, Computer graphics, Light scattering, Particle systems, Radiative transport, Raster graphics, Ray tracing, Simulation of natural phenomena, Stochastic modeling