Efficient light scattering through thin semi-transparent objects |
| | Abstract | This paper concerns real-time rendering of thin semi-transparent
objects. An object in this category could be a piece of cloth, eg. a
curtain. Semi-transparent objects are visualized most correctly
using volume rendering techniques. In general such techniques are,
however, intractable for real-time applications. Surface rendering
is more efficient, but also inadequate since semi-transparent
objects should have a different appearance depending on whether they
are front-lit or back-lit. The back-lit side of a curtain, for
example, often seems quite transparent while the front-lit side
seems brighter and almost opaque. To capture such visual effects in
the standard rendering pipeline, Blinn [1982] proposed
an efficient local illumination model based on radiative transfer
theory. He assumed media of low density, hence, his equations can
render media such as clouds, smoke, and dusty surfaces. Our
observation is that Chandrasekhar [1960] has derived
the same equations from a different set of assumptions. This
alternative derivation makes the theory useful for realistic
real-time rendering of dense, but thin, semi-transparent objects
such as cloth. We demonstrate that application of the theory in this
new area gives far better results than what is obtainable with a
traditional real-time rendering scheme using a constant factor for
alpha blending. | | Keywords | cloth rendering, global illumination, optically thin media, real-time rendering, semi-transparent surfaces | | Type | Conference paper [With referee] | | Conference | Proceedings of GRAPHITE 2005 | | Editors | David Arnold and Mark Billinghurst | | Year | 2005 Month November pp. 135-138 | | Publisher | The Association for Computing Machinery, Inc. (ACM) | | ISBN / ISSN | 1595932011 | | Electronic version(s) | [pdf] | | BibTeX data | [bibtex] | | IMM Group(s) | Image Analysis & Computer Graphics |
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