\section{Todo List}\label{todo}
\label{_todo000004}
\begin{description}
\item[Class {\bf TLine} ]
 Add a rendering class for the Two Level Ray Caster. \end{description}


\label{_todo000005}
\begin{description}
\item[Class {\bf TTransfer} ]
 Refine {\em near\-Line} to find all lines. \end{description}


\label{_todo000001}
\begin{description}
\item[Class {\bf TTransfer\-Form} ]
Change file extension from {\bf .xml} to {\bf .vtr} (Volume Transferfunction. 

 Add Transfer-View packground to file save and load. \end{description}


\label{_todo000003}
\begin{description}
\item[Class {\bf TTwo\-Level\-Form} ]
Adjustable reference (intensity) value for {\bf Average Ray Caster}. 

Threshold value for {\bf NPR Ray Caster}. 

Separate power for border value for {\bf NPR Ray Caster} from phong shading power. 

{\bf Stop}, {\bf start} and {\bf restart} buttons (How should stop be handled? Reset? Continue?). 

Save and Load TL ray caster setting. 

 Export images. \end{description}


\label{_todo000010}
\begin{description}
\item[Member {\bf TTwo\-Level\-Form::\_\-get\-Gradient}(vectord \&v) ]
Reconstruct gradient instead of interpolating it. 

 Calculate interval length to harmonize {\em \_\-draw\-Image} calculation time. \end{description}


\label{_todo000009}
\begin{description}
\item[Member {\bf TTwo\-Level\-Form::\_\-render\-Image}() ]
code a two level ray caster. 

 adjust ray caster, so it can handle any resolution (others than sqares with a size of a multiple of 2). \end{description}


\label{_todo000006}
\begin{description}
\item[Member {\bf TTwo\-Level\-Form::\_\-actres} ]
 adjust the ray casting algorythm in a way, so it can handle any target resolution. \end{description}


\label{_todo000008}
\begin{description}
\item[Member {\bf TTwo\-Level\-Form::\_\-first\-Hit} ]
 Think about a alternative method to render multiple regions with first hit. How should the threshold be defined then? \end{description}


\label{_todo000007}
\begin{description}
\item[Member {\bf TTwo\-Level\-Form::\_\-rpc} ]
 adjust the value by mesuring the time needed for the actual number or rays. \end{description}


\label{_todo000002}
\begin{description}
\item[Member {\bf PREVIEW\_\-SIZE} ]
 get resolution of preview image by measuring the cpu performance. \end{description}
 