Perspective Splatting
J. Edward Swan II, Klaus Mueller, Torsten Möller, Naeem Shareef, Roger Crawfis, and Roni Yagel. Perspective Splatting. Memorandum Report NRL/MR/5580--99-8355, Naval Research Laboratory, 1999.
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Abstract
Splatting is a popular direct volume rendering algorithm that was originally conceived and implemented to render orthographic projections. This paper describes an anti-aliasing extension to the basic splatting algorithm, as well as an error analysis, that make it practical to use for perspective projections. To date, splatting has not correctly rendered cases where the volume sampling rate is higher than the image sampling rate (e.g. more than one voxel maps into a pixel). This situation arises with perspective projections of volumes, as well as with orthographic projections of high-resolution volumes. The result is potentially severe spatial and temporal aliasing artifacts. Some volume ray-casting algorithms avoid these artifacts by employing reconstruction kernels which vary in width as the rays diverge. Unlike ray-casting algorithms, existing splatting algorithms do not have an equivalent mechanism for avoiding these artifacts. In this paper we propose such a mechanism, which delivers high-quality splatted images and has the potential for a very efficient hardware implementation. In addition, we analyze two numerical errors that arise with splatted perspective projections of volumes, and describe the rendering-time versus image-quality tradeoffs of addressing these errors.
BibTeX
@TechReport{TR99-ps,
author = {J. Edward {Swan~II} and Klaus Mueller and Torsten M\"{o}ller and
Naeem Shareef and Roger Crawfis and Roni Yagel},
title = {Perspective Splatting},
institution = {Naval Research Laboratory},
type = {Memorandum Report},
number = {NRL/MR/5580--99-8355},
month = {May},
year = 1999,
abstract = {
Splatting is a popular direct volume rendering algorithm that was originally
conceived and implemented to render orthographic projections. This paper
describes an anti-aliasing extension to the basic splatting algorithm, as well
as an error analysis, that make it practical to use for perspective
projections. To date, splatting has not correctly rendered cases where the
volume sampling rate is higher than the image sampling rate (e.g. more than one
voxel maps into a pixel). This situation arises with perspective projections of
volumes, as well as with orthographic projections of high-resolution
volumes. The result is potentially severe spatial and temporal aliasing
artifacts. Some volume ray-casting algorithms avoid these artifacts by employing
reconstruction kernels which vary in width as the rays diverge. Unlike
ray-casting algorithms, existing splatting algorithms do not have an equivalent
mechanism for avoiding these artifacts. In this paper we propose such a
mechanism, which delivers high-quality splatted images and has the potential for
a very efficient hardware implementation. In addition, we analyze two numerical
errors that arise with splatted perspective projections of volumes, and describe
the rendering-time versus image-quality tradeoffs of addressing these errors.
},
}