如何绘制堆叠在一起的 3D 块，而无需关心在 Tikz 上绘制这些块的顺序

Question

我正在尝试绘制相邻的立方体形状。如果我不按顺序指定坐标，则后续形状的线条将覆盖前一个形状的线条，如下所示。我该如何处理此问题而不必担心绘制顺序？

\documentclass{standalone}
\usepackage{tikz}
\usepackage{tikz-3dplot}
\begin{document}

\tdplotsetmaincoords{50}{60}
\begin{tikzpicture}
        [tdplot_main_coords,
            cube/.style={very thick,black},
            grid/.style={very thin,gray},
            axis/.style={->,blue,thick}]

    %draw a grid in the x-y plane
    \foreach \x in {-1,0,...,4.5}
        \foreach \y in {-1,0,...,4.5}
        {
            \draw[grid] (\x,-1) -- (\x,4.5);
            \draw[grid] (-1,\y) -- (4.5,\y);
        }
            

    %draw the axes
    \draw[axis] (0,0,0) -- (8,0,0) node[anchor=west]{$x$};
    \draw[axis] (0,0,0) -- (0,8,0) node[anchor=west]{$y$};
    \draw[axis] (0,0,0) -- (0,0,8) node[anchor=west]{$z$};

    %draw the edges of the cube
    \foreach \x/\y/\z in {0/0/0,0/1/0,0/2/0}
    {
    \draw [fill=gray!30] (\x,\y,\z)--++(0,0,1)--++(0,1,0)--++(0,0,-1)--cycle;    %x
    \draw [fill=gray!30] (\x,\y,\z)--++(1,0,0)--++(0,1,0)--++(-1,0,0)--cycle;    %z
    \draw [fill=gray!30] (\x,\y,\z)--++(1,0,0)--++(0,0,1)--++(-1,0,0)--cycle;    %y
    \draw [fill=gray!30] (\x,\y+1,\z)--++(1,0,0)--++(0,0,1)--++(-1,0,0)--cycle;    %y
    \draw [fill=gray!30] (\x+1,\y,\z)--++(0,0,1)--++(0,1,0)--++(0,0,-1)--cycle;    %x
    \draw [fill=gray!30] (\x,\y,\z+1)--++(1,0,0)--++(0,1,0)--++(-1,0,0)--cycle;    %z
    }
    
    
\end{tikzpicture}

\end{document}