%*******************************************************************************
% Running head
%
% Replace [AUTHOR(S)] with last name of author.  If two authors, separate last
% names by "and" (e.g., Foo and Bar).  For three or more authors, use the first
% author followed by "et al." (e.g., Foo et al.).
%
% Replace [TITLE] with the article title.
%*******************************************************************************
\markboth{journal of graphics tools}{Nunes et al.: Rendering Tubes from Discrete Curves with Anti-Aliasing and Continuous LOD with Hardware Tessellation}


%*******************************************************************************
% Title / Author
%
% Replace [TITLE] with the article title.
%
% Replace [AUTHOR(S)] with the author.  If two author(s) with the SAME affiliation,
% separate the names using "and" (e.g., John Doe and Jane Doe).  For three or more
% authors with the SAME affiliation, separate names by commas and preceding the
% final name with "and" (e.g., John Doe, Jane Doe, and Foo Bar).
%
% If authors have different affiliations, uncomment the lines for ADDITIONAL
% AUTHORS and AFFILIATION. Format as described above but group authors with
% the same affiliation. If additional affiliations are needed, copy the two
% commented lines for author and affiliation as needed.
%*******************************************************************************
\title{Rendering Tubes from Discrete Curves with Anti-Aliasing and Continuous LOD with Hardware Tessellation}

\label{start}

\author{Gustavo Nunes, Alexandre Valdetaro, Alberto Raposo, and Bruno Feijó}

\date{Pontifical Catholic University of Rio de Janeiro, Dept. of Informatics}

\maketitle

%*******************************************************************************
% ADDITIONAL AUTHORS AND AFFILIATION
%*******************************************************************************
%\vspace*{-4.5pc} % remove extra space after \maketitle

% copy and paste the following two lines as needed
\noindent {\helR Rodrigo de Toledo}
\noindent {\helRE Federal University of Rio de Janeiro, DCC}

%\vspace*{5pc} % manually put back spacing removed from above


%*******************************************************************************
% Abstract
%*******************************************************************************
\begin{abstract}
ABSTRACT
\end{abstract}

%*******************************************************************************
% Article
\pagestyle{myheadings}
%*******************************************************************************
[ARTICLE TEXT]

\section{Introduction}

3D Tubes can be a solution for a multitude of problems in a wide range of areas. To illustrate such cases we will walk through some examples. Visualization of the path taken by particles in time, in the form of streamlines is an appropriate case. Flow simulation is another example of this kind of application (Stoll et al., 2005). In medicine, there are multiple applications which can make use of tubes, for example visualization of white matter tracts (Merhof et al., 2006) and heart fibrillation (Kondratieva et al., 2005). In physics, vector fields can also be viewed as a group of tubes. In the oil industry, tubes can also be used in 3D simulations and for rendering specific real objects. Such real objects as wells and risers can be rendered as 3D tubes and were the main motivation for the technique, as shown in Figure 1. 

3D tubes are represented through a set of points in R3 and a scalar for its radius. In the conventional graphics pipeline, one needs to construct a polygonal mesh based on this representation before sending it to the GPU. There are also ray-casting approaches of 3D tubes rendering demonstrated to be too ALU intensive for thousands of tubes and they also may provide some unwanted artifacts (de Toledo and Levy, 2004). A naive approach such as rendering the tubes as simple lines is reasonable from the performance point of view but lacks in visual quality and suffers with aliasing.

\vspace{24pt} \noindent\textbf{Acknowledgments.}\small \quad ACKNOWLEDGEMENTS


%*******************************************************************************
% References
%
% Replace [BIBLIOGRAPHY] with \bibitem entries.  If you are familiar with the
% use of BibTeX, you can optionally use the akpbib.bst file provided.
%*******************************************************************************
\begin{thebibliography}{99}
[BIBLIOGRAPHY]

\end{thebibliography}


%*******************************************************************************
% Web Information
%
% Copy and paste the lines for author contact information for each author of
% the article and replace the place holders as indicated.
%*******************************************************************************
\section*{Web Information:}\small
[WEB INFO]

% author contact information
\vspace*{12pt}\noindent [AUTHOR], [AFFILIATION], [ADDRESS]
\newline ([EMAIL])

% [DATE]s will be filled-in by managing editor during final production.
% Please ignore.
\vspace*{24pt}\noindent Received [DATE]; accepted [DATE].

\label{end} % DO NOT REMOVE. Provides \pageref for determining last page number.
