CSDL Home IEEE Transactions on Visualization & Computer Graphics 2010 vol.16 Issue No.06 - November/December

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Issue No.06 - November/December (2010 vol.16)

pp: 1487-1494

Alexandre Ancel , University of Strasbourg

Stéphane Marchesin , UC Davis

Amel Guetat , University of Strasbourg

DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TVCG.2010.187

ABSTRACT

Shading is an important feature for the comprehension of volume datasets, but is difficult to implement accurately. Current techniques based on pre-integrated direct volume rendering approximate the volume rendering integral by ignoring non-linear gradient variations between front and back samples, which might result in cumulated shading errors when gradient variations are important and / or when the illumination function features high frequencies. In this paper, we explore a simple approach for pre-integrated volume rendering with non-linear gradient interpolation between front and back samples. We consider that the gradient smoothly varies along a quadratic curve instead of a segment in-between consecutive samples. This not only allows us to compute more accurate shaded pre-integrated look-up tables, but also allows us to more efficiently process shading amplifying effects, based on gradient filtering. An interesting property is that the pre-integration tables we use remain two-dimensional as for usual pre-integrated classification. We conduct experiments using a full hardware approach with the Blinn-Phong illumination model as well as with a non-photorealistic illumination model.

INDEX TERMS

direct volume rendering, pre-integration, gradient interpolation

CITATION

Alexandre Ancel, Stéphane Marchesin, Amel Guetat, "Pre-Integrated Volume Rendering with Non-Linear Gradient Interpolation",

*IEEE Transactions on Visualization & Computer Graphics*, vol.16, no. 6, pp. 1487-1494, November/December 2010, doi:10.1109/TVCG.2010.187REFERENCES