83 lines
No EOL
3.5 KiB
TeX
83 lines
No EOL
3.5 KiB
TeX
\section{Problems}
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\begin{frame}
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\centering
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\Huge
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Problems
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\end{frame}
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\subsection{Why differentiable rendering is hard}
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\begin{frame}{Why differentiable rendering is hard}
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\begin{itemize}
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\item Rendering integral contains the geometry term that is not differentiable
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\item The gradiant of the visibility can lead to dirac delta terms which have 0 probability of being sampled correctly [\cite{ACM:diracdelta},\cite{ACM:diffable_raytracing}]
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\item Differentiation with respect to certain scene parameters possible but we need to differentiate with respect to any scene parameter
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\end{itemize}
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\end{frame}
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\begin{frame}{primary occlusion}
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\centering
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\input{presentation/diagrams/diagramm_occlusion.tex}
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\end{frame}
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\begin{frame}{Angle change $\leftrightarrow$ visibility change}
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\centering
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\input{presentation/diagrams/geometry_term_diff.tex}
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\end{frame}
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\subsection{Former methods}
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\begin{frame}{Former methods}
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\begin{block}{Previous differentiable renderers considered by this paper}
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\begin{itemize}
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\item OpenDR [\cite{DBLP:OpenDR}]
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\item Neural 3D Mesh Renderer [\cite{DBLP:Neural3DKatoetal}]
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\item Both rasterization based (first render the image using rasterization, then approximate the gradients using the resulting color buffer)
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\item Focused on speed rather than precision
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\end{itemize}
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\end{block}
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\end{frame}
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\begin{frame}{Former methods - visualization}
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\begin{figure}
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\begin{minipage}{0.12\linewidth}
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\begin{figure}
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\centering
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\includegraphics[width=\linewidth]{presentation/img/comparisons/plane.png}
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\caption{planar scene}
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\label{fig:planar-scene}
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\end{figure}
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\end{minipage}
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\hspace{2mm}
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\begin{minipage}{0.12\linewidth}
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\begin{figure}
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\centering
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\includegraphics[width=\linewidth]{presentation/img/comparisons/opendr.png}
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\caption{OpenDR}
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\label{fig:grad-OpenDR}
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\end{figure}
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\end{minipage}
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\hspace{2mm}
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\begin{minipage}{0.12\linewidth}
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\begin{figure}
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\centering
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\includegraphics[width=\linewidth]{presentation/img/comparisons/Neural.png}
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\caption{Neural}
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\label{fig:grad-Neural3DMesh}
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\end{figure}
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\end{minipage}
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\hspace{2mm}
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\begin{minipage}{0.12\linewidth}
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\begin{figure}
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\centering
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\includegraphics[width=\linewidth]{presentation/img/comparisons/ours.png}
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\caption{this paper}
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\label{fig:grad-this}
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\end{figure}
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\end{minipage}
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\hspace{4mm}
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\begin{minipage}{0.3\linewidth}
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\caption{
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%A plane lit by a point light source. Images visualize a gradient with respect to the plane moving right. Since the light source remains static the gradient should only be $\ne 0$ at the boundaries. OpenDR and Neural are not able to correctly calculate the gradients as they are based on color buffer differences.\\
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Visualizations of gradients calculated by different differentiable renderers.\\
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Images: \cite{ACM:diffable_raytracing}
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}
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\label{fig:grad-explanation}
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\end{minipage}
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\end{figure}
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\pause
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$\implies$ Problems are caused at the edges and by approximation using color buffers
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\end{frame} |