3D buried view in Tikz

Question

I want to achieve 3D effect in my picture. This is to show Electron beam lithography followed by lift-off process. I want to make a cross shaped hole in the top layer and fill it with a gray color material till half. How to achieve this with opacity and shading?

Thanks

    \documentclass[pdf]{beamer}
    \mode<presentation>{\usetheme{Warsaw}} 
    \usepackage{animate}
    \usepackage{amsmath}
    \usepackage{tikz}
    \title[]{My Presentation}
    \author[Raghuram Dharmavarapu]{Raghu}
    \date{}

    \usetikzlibrary{arrows,snakes,shapes,fadings}
\begin{document}
\begin{frame}[fragile,t]
\frametitle{Fabrication of Metasurface}
\hspace{-0.5cm}
\begin{minipage}{0.44\textwidth}
\underline{Fabrication flow:}
\vspace{0.5cm}
\fontsize{10pt}{14pt}
\begin{enumerate}
\item<1-> \only<1>{\color{red!70!black}}Glass substrate
\item<2-> \only<2>{\color{red!70!black}}Resist spin-coating
\item<3-> \only<3>{\color{red!70!black}}Electron beam Lithography
\item<4-> \only<4>{\color{red!70!black}}Development
\item<5-> \only<5>{\color{red!70!black}}RF Sputtering(Silicon)
\item<6-> \only<6>{\color{red!70!black}}Lift-Off
\end{enumerate}
\end{minipage}
\begin{minipage}{0.55\textwidth}
\begin{tikzpicture}[scale = 0.74]
\onslide<1->
    \useasboundingbox (0.5,0) rectangle (10,8);
    \filldraw[blue!40!black] (1.5,1) -- (9.5,1) -- (9.75,1.5) --(1.25,1.5)--cycle;
    \shade[top color = blue!40!white, bottom color = blue!40!white!70] (1.25,1.5) --(9.75,1.5) -- (8,3.7) -- (3,3.7) --cycle;

\onslide<2,3,4,5>
\filldraw[blue!60!green,opacity = 0.6] (1.25,1.5) rectangle (9.75,1.75);
\shade[top color = blue!60!green!70, bottom color = blue!60!green!70,opacity = 0.6] (1.25,1.75) --(9.75,1.75) -- (8.03,3.81) -- (2.97,3.81) --cycle;

\onslide<3,4>
\begin{scope}[shift = {(3,4)}]
\shade[inner color=red!70!black, top color=red!75!white] (2.2,1.8)
    -- ++(0.6,0) -- ++(-0.3,-1.8) -- cycle;
  \shade[left color=gray!50!white,right color=gray] (1.7,3)
    -- ++(1.6,0) -- ++(-0.3,-1) -- ++(-1,0) -- cycle;
  \shade[left color=gray!50!white,right color=gray] (2.1,2)
    -- ++(0.8,0) -- ++(0,-0.2) -- ++(-0.8,0) -- cycle;
  \draw[gray!80!black] (1.7,3) -- ++(1.6,0) -- ++(-0.3,-1)
    -- ++(-1,0) -- cycle;
  \draw[gray!80!black] (2.1,2) -- ++(0,-0.2) -- ++(0.8,0)
    -- ++(0,0.2);
  \node[thick,red!70!black] at ( -0,2) {\footnotesize Electron Gun};
\end{scope}
\onslide<4>
\foreach \x/\y in {0/0,0.7/0.5,-0.7/-0.5, -1/0, 1/0,0.7/-0.5,-0.7/0.5,0/0.7,0/-0.7}
{
\begin{scope}[shift = {(4.5+\x,1.4+\y)},scale = 1,opacity = 1]
     \clip[scale = 0.08,postaction={fill=blue!40!black}] 
     (11,16-2) -- (14,16-2) -- (13.9,17-2) 
     -- (15.5,17-2) --(15.2,18.25-2)
     --(13.7,18.25-2)--(13.6,19-2)--
     (11.4,19-2)--(11.3,18.25-2)--(9.8,18.25-2)
     --(9.5,17-2)--(11.1,17-2)--cycle;
     \fill[blue,scale = 0.08] (9.8,18.25-3) --(9.8,18.25-2)
     --(9.5,17-2) --(9.5,17-3);
     \filldraw[blue!60!white,scale = 0.08] (11.3,18.25-2) -- (11.3,18.25-3)
     --(9.8,18.25-3) --(9.8,18.25-2);
     \fill[blue,scale = 0.08] (11.3,18.25-2) -- (11.3,18.25-3)
     --(11.4,19-3) --(11.4,19-2);
     \filldraw[blue!60!white,scale = 0.08] (11.4,19-2) --(13.6,19-2) --(13.6,19-3) -- (11.4,19-3);
     \fill[blue!60!green!70,scale = 0.08]
     (13.6,19-2) --(13.7,18.25-2) --(13.7,18.25-3) --(13.6,19-3);
     \filldraw[blue!60!white,scale = 0.08]
     (13.7,18.25-2) --(15.2,18.25-2) --(15.2,18.25-3)
     --(13.7,18.25-3);
     \fill[blue!60!green!70,scale = 0.08]
     (15.2,18.25-2) --(15.2,18.25-3)--(15.5,17-3)--(15.5,17-2);
\end{scope}
}

\onslide<5>
\foreach \x/\y in {0/0,0.7/0.5,-0.7/-0.5, -1/0, 1/0,0.7/-0.5,-0.7/0.5,0/0.7,0/-0.7}
{
\begin{scope}[shift = {(4.5+\x,1.4+\y)},scale = 1,opacity = 1]
     \clip[scale = 0.08,postaction={fill=black!30!white}] 
     (11,16-2) -- (14,16-2) -- (13.9,17-2) 
     -- (15.5,17-2) --(15.2,18.25-2)
     --(13.7,18.25-2)--(13.6,19-2)--
     (11.4,19-2)--(11.3,18.25-2)--(9.8,18.25-2)
     --(9.5,17-2)--(11.1,17-2)--cycle;
     \fill[blue,scale = 0.08] (9.8,18.25-3) --(9.8,18.25-2)
     --(9.5,17-2) --(9.5,17-3);
     \filldraw[blue!60!white,scale = 0.08,draw = blue!70!white ] (11.3,18.25-2) -- (11.3,18.25-3) --(9.8,18.25-3) --(9.8,18.25-2);
5     \fill[blue,scale = 0.08] (11.3,18.25-2) -- (11.3,18.25-3)
     --(11.4,19-3) --(11.4,19-2);
     \filldraw[blue!60!white,scale = 0.08,draw = blue!70!white ] (11.4,19-2) --(13.6,19-2) --(13.6,19-3) -- (11.4,19-3);
     \fill[blue!60!green!70,scale = 0.08]
     (13.6,19-2) --(13.7,18.25-2) --(13.7,18.25-3) --(13.6,19-3);
     \filldraw[blue!60!white,scale = 0.08,draw = blue!70!white ]
     (13.7,18.25-2) --(15.2,18.25-2) --(15.2,18.25-3)
     --(13.7,18.25-3);
     \fill[blue!60!green!70,scale = 0.08,draw = blue!70!white ]
     (15.2,18.25-2) --(15.2,18.25-3)--(15.5,17-3)--(15.5,17-2);
\end{scope}
}
\filldraw[bottom color = gray!20!white, top color = gray!80!white] (4.75,6.5) rectangle (6.25,6.75);
\filldraw[orange!80!black,rotate = 50, shift = {(0.3,-8.5)}] (8,4.5) rectangle (8.25,3);
\draw[thick,orange,->,densely dashed] (8.5,3.85) -- (5,6.5);
\draw[thick,orange,->,densely dashed] (8.5,3.85) -- (5.5,6.5);
\draw[thick,orange,->,densely dashed] (8.5,3.85) -- (6,6.5);
\node[thick,red!70!black] at (9.25,4.25) {\footnotesize Ions};
\foreach \x/\y in {0/0,0.5/-0.5,-0.8/-1,0.8/-1.5,-1.5/-0.8,-2.1/-3,-1.5/-4,1.4/-4.2,
0/-5,2/-3.5,-0.2/-3.2,0.4/-2.1,-1/-5.5,0.9/-5.1,-3/-6,-3.5/-7.2,
-0.5/-5.6,2.7/-6.2,0/-7.5}
{
\node[circle,shading=ball,minimum size=0.1mm,scale = 0.3,ball color = gray!80,shift = {(\x,\y)}] (ball) at (5.5,6.25) {};
}
\node[red!80!black] at (8,6.675) {\footnotesize Silicon target} ;
\onslide<6->
\foreach \x/\y in {0/0,0.7/0.5,-0.7/-0.5, -1/0, 1/0,0.7/-0.5,-0.7/0.5,0/0.7,0/-0.7}
{
\begin{scope}[shift = {(4.5+\x,1.4+\y)},scale = 1,opacity = 1]
    \filldraw[gray!30!white,scale = 0.08] (11,16) -- (14,16) -- (13.9,17) -- (15.5,17) --(15.2,18.25)--(13.7,18.25)--(13.6,19)--(11.4,19)--(11.3,18.25)--(9.8,18.25)--(9.5,17)--(11.1,17)--cycle;
    \filldraw[gray!90!white,scale = 0.08] (9.5,17)--(9.6,15.5)--(11.05,15.5)--(11,16)--(11.1,17)--cycle;
    \filldraw[gray!90!black,scale = 0.08] (11,16) -- (11.1,15) -- (13.9,15) -- (14,16)-- cycle;
    \filldraw[gray!90!white,scale = 0.08] (15.5,17) --(15.4,15.5) --(13.95,15.5) --(14,16) -- (13.9,17) --cycle;
\end{scope}
}
\onslide<1->
\end{tikzpicture}
\end{minipage}
\end{frame}

\end{document}

EDIT

I was able to achieve what I wanted shown in below figure. But when I actually copied it into my main tex file it is behaving strangely, it is showing comingup onslide material in white color over existing slides. I was using \setbeamercovered in one of my slides in my main tex file. If I remove that slide its working perfectly but when I include it it is causing problem like shown below.

Working solution in separate text file.

When copied into main text it is giving output as

EDIT

I solved it by using \setbeamercovered{invisible} command.

Answer 1

You could do something like this:

\documentclass[pdf]{beamer}
\mode<presentation>{\usetheme{Warsaw}} 
\usepackage{animate}
\usepackage{amsmath}
\usepackage{tikz}
\title[]{My Presentation}
\author[Raghuram Dharmavarapu]{Raghu}
\date{}

\usetikzlibrary{arrows,snakes,shapes,fadings}
\begin{document}
   \begin{frame}
\frametitle{Fabrication of Metasurface}
\begin{tikzpicture}[scale = 1]
\onslide<1->
    \useasboundingbox (0,0) rectangle (10,8);
    \begin{scope}
    \filldraw[blue!40!black] (1.5,1) -- (9.5,1) -- (9.75,1.5) --(1.25,1.5)--cycle;
    \shade[top color = blue!40!white, bottom color = blue!40!white!70] (1.25,1.5) --(9.75,1.5) -- (8,3.5) -- (3,3.5) --cycle;
    \end{scope}

\onslide<2->
\filldraw[blue!60!green,opacity = 0.6] (1.25,1.5) rectangle (9.75,1.75);
 \shade[top color = blue!60!green!70, bottom color = blue!60!green!70,opacity = 0.6] (1.25,1.75) --(9.75,1.75) -- (8.03,3.61) -- (2.97,3.61) --cycle;

\onslide<3>
\begin{scope}[shift = {(3,4)}]
\shade[inner color=red!70!black, top color=red!75!white] (2.2,1.8)
    -- ++(0.6,0) -- ++(-0.3,-1.8) -- cycle;
  \shade[left color=gray!50!white,right color=gray] (1.7,3)
    -- ++(1.6,0) -- ++(-0.3,-1) -- ++(-1,0) -- cycle;
  \shade[left color=gray!50!white,right color=gray] (2.1,2)
    -- ++(0.8,0) -- ++(0,-0.2) -- ++(-0.8,0) -- cycle;
  \draw[gray!80!black] (1.7,3) -- ++(1.6,0) -- ++(-0.3,-1)
    -- ++(-1,0) -- cycle;
  \draw[gray!80!black] (2.1,2) -- ++(0,-0.2) -- ++(0.8,0)
    -- ++(0,0.2);
\end{scope}
\onslide<4->
\begin{scope}[shift = {(1,-1.3)},scale = 3,opacity = 1]
%     \filldraw[gray!50!white,scale = 0.08] (11,16) -- (14,16) -- (13.9,17) -- (15.5,17) --(15.2,18.25)--(13.7,18.25)--(13.6,19)--(11.4,19)--(11.3,18.25)--(9.8,18.25)--(9.5,17)--(11.1,17)--cycle;
% 
% 
%      \filldraw[gray!70!white,scale = 0.08] (11,16) -- (14,16) -- (13.9,17) -- (13.7,18.25)--(11.3,18.25)--(11.1,17)--cycle;
%      \filldraw[blue!60!green!70,scale = 0.08] (9.5,17)--(9.6,14.5)--(11.05,14.5)--(11,16)--(11.1,17)--cycle;
%     \filldraw[blue!60!green,scale = 0.08] (11,16) -- (11.1,14) -- (13.9,14) -- (14,16)-- cycle;
%     \filldraw[blue!60!green!70,scale = 0.08] (15.5,17) --(15.4,14.5) --(13.95,14.5) --(14,16) -- (13.9,17) --cycle;

     \clip[scale = 0.08,postaction={fill=blue!40!black}] 
     (11,16-2) -- (14,16-2) -- (13.9,17-2) 
     -- (15.5,17-2) --(15.2,18.25-2)
     --(13.7,18.25-2)--(13.6,19-2)--
     (11.4,19-2)--(11.3,18.25-2)--(9.8,18.25-2)
     --(9.5,17-2)--(11.1,17-2)--cycle;
     \fill[blue,scale = 0.08] (9.8,18.25-3) --(9.8,18.25-2)
     --(9.5,17-2) --(9.5,17-3);
     \filldraw[blue!60!white,scale = 0.08] (11.3,18.25-2) -- (11.3,18.25-3)
     --(9.8,18.25-3) --(9.8,18.25-2);
     \fill[blue,scale = 0.08] (11.3,18.25-2) -- (11.3,18.25-3)
     --(11.4,19-3) --(11.4,19-2);
     \filldraw[blue!60!white,scale = 0.08] (11.4,19-2) --(13.6,19-2) --(13.6,19-3) -- (11.4,19-3);
     \fill[blue!60!green!70,scale = 0.08]
     (13.6,19-2) --(13.7,18.25-2) --(13.7,18.25-3) --(13.6,19-3);
     \filldraw[blue!60!white,scale = 0.08]
     (13.7,18.25-2) --(15.2,18.25-2) --(15.2,18.25-3)
     --(13.7,18.25-3);
     \fill[blue!60!green!70,scale = 0.08]
     (15.2,18.25-2) --(15.2,18.25-3)--(15.5,17-3)--(15.5,17-2);
\end{scope}
\end{tikzpicture}
\end{frame}
\end{document}

However, I would really like to draw your attention to this great answer, which allows you to draw things in 3d perspective. If I was you, I would redraw your diagram with these tools.

\documentclass[pdf]{beamer}
\mode<presentation>{\usetheme{Warsaw}} 
\usepackage{animate}
\usepackage{amsmath}
\usepackage{tikz}
\usepackage{tikz-3dplot}
\usetikzlibrary{overlay-beamer-styles}
\usepgfmodule{nonlineartransformations}
% Max magic
\makeatletter 
% the first part is not in use here
\def\tikz@scan@transform@one@point#1{%
  \tikz@scan@one@point\pgf@process#1%
  \pgf@pos@transform{\pgf@x}{\pgf@y}}
\tikzset{%
  grid source opposite corners/.code args={#1and#2}{%
   \pgfextract@process\tikz@transform@source@southwest{%
     \tikz@scan@transform@one@point{#1}}%
   \pgfextract@process\tikz@transform@source@northeast{%
     \tikz@scan@transform@one@point{#2}}%
  },
  grid target corners/.code args={#1--#2--#3--#4}{%
   \pgfextract@process\tikz@transform@target@southwest{%
     \tikz@scan@transform@one@point{#1}}%
   \pgfextract@process\tikz@transform@target@southeast{%
     \tikz@scan@transform@one@point{#2}}%
   \pgfextract@process\tikz@transform@target@northeast{%
     \tikz@scan@transform@one@point{#3}}%
   \pgfextract@process\tikz@transform@target@northwest{%
     \tikz@scan@transform@one@point{#4}}%
  }
}

\def\tikzgridtransform{%
  \pgfextract@process\tikz@current@point{}%
  \pgf@process{%
    \pgfpointdiff{\tikz@transform@source@southwest}%
      {\tikz@transform@source@northeast}%
  }%
  \pgf@xc=\pgf@x\pgf@yc=\pgf@y%
  \pgf@process{%
    \pgfpointdiff{\tikz@transform@source@southwest}{\tikz@current@point}%
  }%
  \pgfmathparse{\pgf@x/\pgf@xc}\let\tikz@tx=\pgfmathresult%
  \pgfmathparse{\pgf@y/\pgf@yc}\let\tikz@ty=\pgfmathresult%
  %
  \pgfpointlineattime{\tikz@ty}{%
    \pgfpointlineattime{\tikz@tx}{\tikz@transform@target@southwest}%
      {\tikz@transform@target@southeast}}{%
    \pgfpointlineattime{\tikz@tx}{\tikz@transform@target@northwest}%
      {\tikz@transform@target@northeast}}%
}

% Initialize H matrix for perspective view
\pgfmathsetmacro\H@tpp@aa{1}\pgfmathsetmacro\H@tpp@ab{0}\pgfmathsetmacro\H@tpp@ac{0}%\pgfmathsetmacro\H@tpp@ad{0}
\pgfmathsetmacro\H@tpp@ba{0}\pgfmathsetmacro\H@tpp@bb{1}\pgfmathsetmacro\H@tpp@bc{0}%\pgfmathsetmacro\H@tpp@bd{0}
\pgfmathsetmacro\H@tpp@ca{0}\pgfmathsetmacro\H@tpp@cb{0}\pgfmathsetmacro\H@tpp@cc{1}%\pgfmathsetmacro\H@tpp@cd{0}
\pgfmathsetmacro\H@tpp@da{0}\pgfmathsetmacro\H@tpp@db{0}\pgfmathsetmacro\H@tpp@dc{0}%\pgfmathsetmacro\H@tpp@dd{1}

%Initialize H matrix for main rotation
\pgfmathsetmacro\H@rot@aa{1}\pgfmathsetmacro\H@rot@ab{0}\pgfmathsetmacro\H@rot@ac{0}%\pgfmathsetmacro\H@rot@ad{0}
\pgfmathsetmacro\H@rot@ba{0}\pgfmathsetmacro\H@rot@bb{1}\pgfmathsetmacro\H@rot@bc{0}%\pgfmathsetmacro\H@rot@bd{0}
\pgfmathsetmacro\H@rot@ca{0}\pgfmathsetmacro\H@rot@cb{0}\pgfmathsetmacro\H@rot@cc{1}%\pgfmathsetmacro\H@rot@cd{0}
%\pgfmathsetmacro\H@rot@da{0}\pgfmathsetmacro\H@rot@db{0}\pgfmathsetmacro\H@rot@dc{0}\pgfmathsetmacro\H@rot@dd{1}

\pgfkeys{
    /three point perspective/.cd,
        p/.code args={(#1,#2,#3)}{
            \pgfmathparse{int(round(#1))}
            \ifnum\pgfmathresult=0\else
                \pgfmathsetmacro\H@tpp@ba{#2/#1}
                \pgfmathsetmacro\H@tpp@ca{#3/#1}
                \pgfmathsetmacro\H@tpp@da{ 1/#1}
                \coordinate (vp-p) at (#1,#2,#3);
            \fi
        },
        q/.code args={(#1,#2,#3)}{
            \pgfmathparse{int(round(#2))}
            \ifnum\pgfmathresult=0\else
                \pgfmathsetmacro\H@tpp@ab{#1/#2}
                \pgfmathsetmacro\H@tpp@cb{#3/#2}
                \pgfmathsetmacro\H@tpp@db{ 1/#2}
                \coordinate (vp-q) at (#1,#2,#3);
            \fi
        },
        r/.code args={(#1,#2,#3)}{
            \pgfmathparse{int(round(#3))}
            \ifnum\pgfmathresult=0\else
                \pgfmathsetmacro\H@tpp@ac{#1/#3}
                \pgfmathsetmacro\H@tpp@bc{#2/#3}
                \pgfmathsetmacro\H@tpp@dc{ 1/#3}
                \coordinate (vp-r) at (#1,#2,#3);
            \fi
        },
        coordinate/.code args={#1,#2,#3}{
           \pgfmathsetmacro\tpp@x{#1} %<- Max' fix
            \pgfmathsetmacro\tpp@y{#2}
            \pgfmathsetmacro\tpp@z{#3}
        },
}

\tikzset{
    view/.code 2 args={
        \pgfmathsetmacro\rot@main@theta{#1}
        \pgfmathsetmacro\rot@main@phi{#2}
        % Row 1
        \pgfmathsetmacro\H@rot@aa{cos(\rot@main@phi)}
        \pgfmathsetmacro\H@rot@ab{sin(\rot@main@phi)}
        \pgfmathsetmacro\H@rot@ac{0}
        % Row 2
        \pgfmathsetmacro\H@rot@ba{-cos(\rot@main@theta)*sin(\rot@main@phi)}
        \pgfmathsetmacro\H@rot@bb{cos(\rot@main@phi)*cos(\rot@main@theta)}
        \pgfmathsetmacro\H@rot@bc{sin(\rot@main@theta)}
        % Row 3
        \pgfmathsetmacro\H@m@ca{sin(\rot@main@phi)*sin(\rot@main@theta)}
        \pgfmathsetmacro\H@m@cb{-cos(\rot@main@phi)*sin(\rot@main@theta)}
        \pgfmathsetmacro\H@m@cc{cos(\rot@main@theta)}
        % Set vector values
        \pgfmathsetmacro\vec@x@x{\H@rot@aa}
        \pgfmathsetmacro\vec@y@x{\H@rot@ab}
        \pgfmathsetmacro\vec@z@x{\H@rot@ac}
        \pgfmathsetmacro\vec@x@y{\H@rot@ba}
        \pgfmathsetmacro\vec@y@y{\H@rot@bb}
        \pgfmathsetmacro\vec@z@y{\H@rot@bc}
        % Set pgf vectors
        \pgfsetxvec{\pgfpoint{\vec@x@x cm}{\vec@x@y cm}}
        \pgfsetyvec{\pgfpoint{\vec@y@x cm}{\vec@y@y cm}}
        \pgfsetzvec{\pgfpoint{\vec@z@x cm}{\vec@z@y cm}}
    },
}

\tikzset{
    perspective/.code={\pgfkeys{/three point perspective/.cd,#1}},
    perspective/.default={p={(15,0,0)},q={(0,15,0)},r={(0,0,50)}},
}

\tikzdeclarecoordinatesystem{three point perspective}{
    \pgfkeys{/three point perspective/.cd,coordinate={#1}}
    \pgfmathsetmacro\temp@p@w{\H@tpp@da*\tpp@x + \H@tpp@db*\tpp@y + \H@tpp@dc*\tpp@z + 1}
    \pgfmathsetmacro\temp@p@x{(\H@tpp@aa*\tpp@x + \H@tpp@ab*\tpp@y + \H@tpp@ac*\tpp@z)/\temp@p@w}
    \pgfmathsetmacro\temp@p@y{(\H@tpp@ba*\tpp@x + \H@tpp@bb*\tpp@y + \H@tpp@bc*\tpp@z)/\temp@p@w}
    \pgfmathsetmacro\temp@p@z{(\H@tpp@ca*\tpp@x + \H@tpp@cb*\tpp@y + \H@tpp@cc*\tpp@z)/\temp@p@w}
    \pgfpointxyz{\temp@p@x}{\temp@p@y}{\temp@p@z}
}
\tikzaliascoordinatesystem{tpp}{three point perspective}

\makeatother
\tikzset{set mark/.style args={#1|#2}{
postaction={decorate,decoration={markings,
mark=at position #1 with {\coordinate(#2);}}}}}
\title[]{My Presentation}
\author[Raghuram Dharmavarapu]{Raghu}
\date{}

\usetikzlibrary{shapes,fadings}
\begin{document}
\foreach \X in {0,0.08,...,0.8,0.72,0.64,...,0}
{\begin{frame}[t]
\frametitle{Fabrication of Metasurface}
\tdplotsetmaincoords{77}{0}
\pgfmathsetmacro{\vq}{5}
\begin{tikzpicture}[scale=pi,%tdplot_main_coords
  view={\tdplotmaintheta}{\tdplotmainphi},
            perspective={
                p = {(0,0,10)},
                q = {(0,\vq,1.25)},
            }
  ]
  \path[tdplot_screen_coords] (-1.5,0.1) rectangle (1.5,2.7);
  \filldraw[blue!40!black]
   (tpp cs:-1,-1,1)  -- (tpp cs:1,-1,1)
   -- (tpp cs:0.9,-0.9,0.8) -- (tpp cs:-0.9,-0.9,0.8) -- cycle;
  \shade[top color = blue!40!white, bottom color = blue!40!white!70] 
  (tpp cs:-1,-1,1)  -- (tpp cs:1,-1,1) -- (tpp cs:1,1,1) -- (tpp cs:-1,1,1) 
  -- cycle;
  %\onslide<2->
  \begin{scope}
   \filldraw[blue!60!green,opacity = 0.6] 
   (tpp cs:-1,-1,1)  -- (tpp cs:1,-1,1)
   -- (tpp cs:1,-1,1.1) -- (tpp cs:-1,-1,1.1)  -- cycle;
   \shade[top color = blue!60!green!70, bottom color = blue!60!green!70,opacity = 0.6] 
    (tpp cs:-1,-1,1.1)  -- (tpp cs:1,-1,1.1) -- (tpp cs:1,1,1.1) -- (tpp cs:-1,1,1.1) 
    -- cycle;
  \end{scope}
  %\onslide<3->
  \begin{scope}[tdplot_screen_coords,shift={(-0.75,1.5)},scale=0.3]
  \shade[inner color=red!70!black, top color=red!75!white] (2.2,1.8)
    -- ++(0.6,0) -- ++(-0.3,-1.8) -- cycle;
  \shade[left color=gray!50!white,right color=gray] (1.7,3)
    -- ++(1.6,0) -- ++(-0.3,-1) -- ++(-1,0) -- cycle;
  \shade[left color=gray!50!white,right color=gray] (2.1,2)
    -- ++(0.8,0) -- ++(0,-0.2) -- ++(-0.8,0) -- cycle;
  \draw[gray!80!black] (1.7,3) -- ++(1.6,0) -- ++(-0.3,-1)
    -- ++(-1,0) -- cycle;
  \draw[gray!80!black] (2.1,2) -- ++(0,-0.2) -- ++(0.8,0)
    -- ++(0,0.2);
  \end{scope}
  %\onslide<4->
  \begin{scope}
   \def\myx{\X}
   \clip[postaction={fill=blue!40!black}]   (tpp cs:\myx-0.1,-0.4,1.1)
   -- (tpp cs:\myx-0.3,-0.4,1.1)   
   -- (tpp cs:\myx-0.3,-0.2,1.1)
   -- (tpp cs:\myx-0.5,-0.2,1.1)
   -- (tpp cs:\myx-0.5,-0.4,1.1)
   -- (tpp cs:\myx-0.7,-0.4,1.1)
   -- (tpp cs:\myx-0.7,-0.6,1.1)
   -- (tpp cs:\myx-0.5,-0.6,1.1)
   -- (tpp cs:\myx-0.5,-0.8,1.1)
   -- (tpp cs:\myx-0.3,-0.8,1.1)
   -- (tpp cs:\myx-0.3,-0.6,1.1)
   -- (tpp cs:\myx-0.1,-0.6,1.1)
   -- cycle;
   \fill[blue!50] (tpp cs:\myx-0.3,-0.2,1) -- (tpp cs:\myx-0.3,-0.2,1.1)
   -- (tpp cs:\myx-0.5,-0.2,1.1) -- (tpp cs:\myx-0.5,-0.2,1)
   -- cycle; % 1
   \fill[blue!60!green!70] (tpp cs:\myx-0.3,-0.4,1.1) -- (tpp cs:\myx-0.3,-0.4,1) 
   -- (tpp cs:\myx-0.3,-0.2,1) -- (tpp cs:\myx-0.3,-0.2,1.1)
   -- cycle; % 2
   \fill[blue!50!black] (tpp cs:\myx-0.5,-0.2,1.1) -- (tpp cs:\myx-0.5,-0.2,1)
    -- (tpp cs:\myx-0.5,-0.4,1) -- (tpp cs:\myx-0.5,-0.4,1.1)
   -- cycle; % 2
   \fill[blue!50] (tpp cs:\myx-0.1,-0.4,1.1)
   -- (tpp cs:\myx-0.3,-0.4,1.1) -- (tpp cs:\myx-0.3,-0.4,1) -- (tpp cs:\myx-0.1,-0.4,1)
   -- cycle; % 3 
   \fill[blue!50]  (tpp cs:\myx-0.5,-0.4,1) -- (tpp cs:\myx-0.5,-0.4,1.1)
   -- (tpp cs:\myx-0.7,-0.4,1.1) -- (tpp cs:\myx-0.7,-0.4,1)
   -- cycle; % 3
   \fill[blue!60!green!70] (tpp cs:\myx-0.1,-0.4,1.1)
   -- (tpp cs:\myx-0.1,-0.6,1.1) -- (tpp cs:\myx-0.1,-0.6,1) -- (tpp cs:\myx-0.1,-0.4,1)
   -- cycle; % 4
   \fill[blue!50!black]  (tpp cs:\myx-0.7,-0.4,1.1) -- (tpp cs:\myx-0.7,-0.4,1)
   -- (tpp cs:\myx-0.7,-0.6,1) -- (tpp cs:\myx-0.7,-0.6,1.1)
   -- cycle; % 4
   \fill[blue!60!green!70] (tpp cs:\myx-0.3,-0.8,1.1) -- (tpp cs:\myx-0.3,-0.8,1) 
   -- (tpp cs:\myx-0.3,-0.6,1) -- (tpp cs:\myx-0.3,-0.6,1.1)
   -- cycle; % 5
   \fill[blue!50!black] (tpp cs:\myx-0.5,-0.6,1.1) -- (tpp cs:\myx-0.5,-0.6,1)
    -- (tpp cs:\myx-0.5,-0.8,1) -- (tpp cs:\myx-0.5,-0.8,1.1)
   -- cycle; % 5
  \end{scope}
\end{tikzpicture}
\end{frame}}
\end{document}

This is to illustrate the advantage of Max' great code: you draw in 3d, and TikZ will compute the perspective projection for you.