# Leave certain part of a tikz-picture uncovered

i have a picture with three circles, see the minimal working example below:

\documentclass{beamer}
\setbeamercovered{transparent}
\usepackage{tikz}

\begin{document}

\begin{frame}
\begin{tikzpicture}
\draw (1,0) circle (1);
\pause
\draw (5,0) circle (1);
\draw (10,0) circle (1);
\end{tikzpicture}
\end{frame}

\end{document}


For certain reasons, i would like to show only the first circle with a continous lins, the other circles should be visible in a semitransparent way. By using the "\pause"-command, i get an image exactly in the way i would like to have it on the first slide, but i do not want the second slide to be generated (because here all three circles are fully visible again).

Is there an option / certain command in order to "highlight" just a certain part of a whole picture? In other words, is there an option for fading out certain areas of an image?

Thanks in advance and best regards!

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Take a look into this approach: tex.stackexchange.com/a/55849/3751 – Daniel Feb 5 '14 at 13:14
I don't understand "By using the "\pause"-command, i get an image exactly in the way i would like to have it on the first slide, but i do not want the second slide to be generated (because here all three circles are fully visible again)." So, you want to display on the first slide one circle and on the second one all the circles, where two of them are transparent? – Claudio Fiandrino Feb 5 '14 at 13:19
I just want to have 1 slide, where the first circle should be totally visible and all others should be semitransparent – pythag0ra5 Feb 5 '14 at 13:28
@pythag0ra5: Hence, no need of overlays. – Claudio Fiandrino Feb 5 '14 at 13:31

If I understand you correctly you could just put the two last circles in a scope and set opacity=0.3 (adjust the value to whatever you like).

\documentclass{beamer}
\setbeamercovered{transparent}
\usepackage{tikz}

\begin{document}
\begin{frame}
\begin{tikzpicture}
\draw (1,0) circle (1);
\begin{scope}[opacity=0.3] % sets opacity to 30% for everything in the scope
\draw (5,0) circle (1);
\draw (10,0) circle (1);
\end{scope}
\end{tikzpicture}
\end{frame}

-
Thanks, i think this is the easiest way for me! – pythag0ra5 Feb 5 '14 at 13:31
In case overlays would have been needed to display transparent circles on slide 2, I suggest the use of aobs-tikz. Just need to change options to the scope environment: \begin{scope}[background aspect={opacity=0.4},aspect on=<2>]. – Claudio Fiandrino Feb 5 '14 at 13:45

Here is one over kill with fadings library:

\documentclass{beamer}
\setbeamercovered{transparent}
\usepackage{tikz}
left color=transparent!10,
right color=transparent!10]

\begin{document}
\begin{frame}
\begin{tikzpicture}
\draw (1,0) circle (1);
\draw (5,0) circle (1);
\draw (10,0) circle (1);
\end{tikzpicture}
\end{frame}
\end{document}


\tikzfading[name=fade left,
left color=transparent!60,
right color=transparent!10]


say. This gives:

\documentclass{beamer}
\setbeamercovered{transparent}
\usepackage{tikz}
left color=transparent!60,
right color=transparent!10]

\begin{document}
\begin{frame}
\begin{tikzpicture}
\draw (1,0) circle (1);
\draw (5,0) circle (1);
\draw (10,0) circle (1);
\end{tikzpicture}
\end{frame}
\end{document}


-

Found on p.234 of TikZ/PGF manual: transparency. There are several ways to implement this. A simple one follows.

\begin{document}

\begin{frame}
\begin{tikzpicture}
\draw (1,0) circle (1);
\pause
\draw [draw opacity=0.3](5,0) circle (1);
\draw [draw opacity=0.3](10,0) circle (1);
\end{tikzpicture}
\end{frame}

\end{document}


If the drawing becomes more complicated, perhaps it would be better to put the opacity into a style?

-
The \pause is unnecessary. – Torbjørn T. Feb 5 '14 at 13:39