Challenge! Create aTikZ style to mimic mirror reflection (with option for curvature distortion)

Question

When we see images that are reflected at a mirror, or at the eyes of someone, or at the water, there is some light effect that tells our brains the image we are seeing is a reflection.

Some of Escher pictures illustrate this very well: or

I'm looking for ideas or suggestions on how to create this effect using TikZ. The concept is to have a style that we could apply to an arbitrary picture to obtain the picture looking as if it were a reflection.

I'm not trying to simply mirror a TikZ picture but rather trying to make appear as if the picture is a reflection. I will post a bounty as soon as I can to reward the best answer. The MWE requirement clearly does not apply here.

Answer 1

Run with latex->dvips->ps2pdf. The image must be an eps type (vector graphics):

\documentclass{article} 
\usepackage{pst-mirror,graphicx}
\begin{document}

 \begin{pspicture}(-5,-5)(5,5)
 \psframe*(-5,-5)(5,5)
 \pscircle*[linecolor=blue!50]{!7 2 sqrt div}
 \psset{Rayon=7}
 \pstSphereImage(5,0,0){tiger.eps}
 \pstSphereGrid[linecolor=white,linewidth=0.01,grille=5,Ymin=-100,Ymax=100,Xmax=100,Xmin=-100](5,0,0)%
 \end{pspicture}

 \reflectbox{\includegraphics[width=4cm]{tiger}}

\end{document}

Answer 2

I'm posting Paul's comment as a community wiki. I would remove it if Paul decides to publish the answer himself.

This is front cover of pgfmanual and the code, well you can find it on the first page of the document! Stand alone version of the page was submitted to TeXample by Ludger Humbert. Copyright of Till Tantau I assume...

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{%
   decorations.fractals%
  ,decorations.pathmorphing%
  ,shadows%
}

\begin{document}
  \parindent0pt
  \null
  \colorlet{mintgreen}{green!50!black!50}

  \thispagestyle{empty}
  \vskip3cm
  \vfill
  \hfil
  \begin{tikzpicture}[overlay]
    \coordinate (front) at (0,0);
    \coordinate (horizon) at (0,.31\paperheight);
    \coordinate (bottom) at (0,-.6\paperheight);
    \coordinate (sky) at (0,.57\paperheight);
    \coordinate (left) at (-.51\paperwidth,0);
    \coordinate (right) at (.51\paperwidth,0);

    \shade [bottom color=blue!30!black!10,top color=blue!30!black!50]
      ([yshift=-5mm]horizon -|  left) rectangle (sky -| right);
    \shade [bottom color=black!70!green!25,top color=black!70!green!10]
      (front -| left) -- (horizon -| left)
      decorate [decoration=random steps] { -- (horizon -| right) }
      -- (front -| right) -- cycle;
    \shade [top color=black!70!green!25,bottom color=black!25]
      (front -| left) -- (horizon -| left)
      decorate [decoration=random steps] { -- (horizon -| right) }
      -- (front -| right) -- cycle;
    \shade [top color=black!70!green!25,bottom color=black!25]
      ([yshift=-5mm-1pt]front -| left) rectangle ([yshift=1pt]front -| right);
    \fill [black!25] (bottom -| left) rectangle ([yshift=-5mm]front -| right);

    \def\nodeshadowed[#1]#2;{\node[scale=2,above,#1]{#2};\node[scale=2,
        above,#1,yscale=-1,scope fading=south,opacity=0.4]{#2};}

    \nodeshadowed [at={(-5,5  )},yslant=0.05]
        {\Huge Ti\textcolor{orange}{\emph{k}}Z};
    \nodeshadowed [at={( 0,5.3)}] {\huge \textcolor{mintgreen}{\&}};
    \nodeshadowed [at={( 5,5  )},yslant=-0.05] {\Huge \textsc{PGF}};
    \nodeshadowed [at={( 0,2  )}] {Manual for Version \pgftypesetversion};

    \foreach \i in {0.5,0.6,...,2}
      \fill [white,decoration=Koch snowflake,opacity=.9]
            [shift=(horizon),shift={(rand*11,rnd*7)},scale=\i]
            [double copy shadow={opacity=0.2,shadow xshift=0pt,shadow
              yshift=3*\i pt,fill=white,draw=none}]
        decorate {
          decorate {
            decorate {
              (0,0) -- ++(60:1) -- ++(-60:1) -- cycle
            }
          }
        };
  \end{tikzpicture}
  \vfill
\end{document}

Answer 3

Just for fun :-)

The code is heavily based on my answer to Help with the design of an eye in TikZ but changed the scale and colors, and added two new reflections.

As you see, the "reflection" technique here is to decrease opacity, and to distort the shapes. The skull is not distorted (this would be difficult), but since the shape to its left is interpreted by the brain as the reflection of a rectangular window, it conveys the information that the reflecting surface is non-flat (spherical ideed).

\documentclass{standalone}
\usepackage{tikz}
\usepackage{skull}
\usepackage{graphicx}
\usetikzlibrary{calc,decorations.pathmorphing}
\begin{document}

\def\eye#1{\scalebox{#1}{
\def\topedge{(-3,0) .. controls (-2,1.8) and (2,2) .. (2.3,.3)}
\def\bottomedge{(2.3,.3) .. controls (2,-2.2) and (-2,-1.2) .. (-3,0)}
\def\eyepath{\topedge -- \bottomedge --cycle;}

\begin{tikzpicture}
  \clip\eyepath;
  % Iris
    \filldraw[color=blue!60!cyan!50!black] (-.2,.2) circle (1.4);
  % Shadow on iris
    \filldraw[color=blue!60!cyan!80!black] (-.3,-.1) circle (1.1);
  % Iris lines
      \foreach \a in {0,5,...,360}{
        \pgfmathparse{25+38*rnd}
        \fill[opacity=0.7, white!\pgfmathresult!blue, decoration={random steps, segment length=3pt, amplitude=1pt}, decorate, line width=1pt  ] (-.2,.2) -- ++($(\a+2*rnd:.9+0.3*rnd)$) -- ++(\a+90:2pt) -- cycle;
      }
  % Pupil
    \fill[color=black] (-.2,.2) circle (0.6);
  % Window reflection
    \fill[color=white, opacity=0.7, shift={(-.4,.4)}] 
    (220:0.65) -- (220:1.25) to[bend left=20] (170:1.15) -- (140:0.65) to[bend right=20] (220:0.65);
  % Skull reflection
    \begin{scope}
        \clip (-.1,.4) circle(0.9);  % Skull reflection
        \node[opacity=0.4] at (-.2,-.1) 
           {\resizebox{20mm}{!}{\textcolor{white}{\Huge$\skull$}}};
    \end{scope}
  % Shadow of the eyelid
    \draw[line width=8mm, draw opacity=0.1, line cap=round]\topedge;
  % Eyelids
    \draw[line width=4mm, red!40!white!80!black, line cap=round]\bottomedge;
    \draw[line width=3mm, red!40!white!60!black, line cap=round]\topedge;
  % Lacrimal
    \fill[red!40!white!80!black] (-2.8,0) circle (.25);
    \fill[white] (-2.7,.1) circle (.03);

\end{tikzpicture}
}}

\eye{1}
\end{document}