Create matrix projection like view

3.tex

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz}
\usepackage{tikz-3dplot}
\usetikzlibrary{backgrounds}
\begin{document}
\tdplotsetmaincoords{65}{60}
\begin{tikzpicture}[tdplot_main_coords]
\begin{scope}[canvas is xz plane at y=2,transform shape]
 \node[inner xsep=-3pt,inner ysep=-0.3pt] (mat1){$\displaystyle
  \begin{bmatrix}
  3  &  9 \\
  6  &  4 \\
  \end{bmatrix}$};
\end{scope}
%
\begin{scope}[canvas is xz plane at y=0,transform shape]
 \node[inner xsep=-4pt,inner ysep=-0.3pt] (mat2){$\displaystyle
  \begin{bmatrix}
  3       &  6 & 2 & 1 \\
  2       & 1  & 9 & 6 \\
  0       & 3  & 0 & 1 \\
  6       & 5  & 2 & 4 \\
  \end{bmatrix}$};
\end{scope}
%
\begin{scope}[on background layer]
 \foreach \Y in {south,north} {\foreach \X in {west,east}
 {\draw (mat1.\Y\space\X)  -- (mat2.\Y\space\X);}}
 \foreach \X in {1,2}
 {\fill[blue!20] (mat\X.west)  -- (mat\X.east) -- (mat\X.south east) 
  -- (mat\X.south) -- (mat\X.north) -- (mat\X.north west) -- cycle; }
\end{scope} 
\end{tikzpicture}
\end{document}