3

Default behavior of Beamer for covered elements is to make them invisible. You can change this to making them transparent by

\documentclass{beamer}
\usepackage{lipsum}
\setbeamercovered{transparent}
% desired command to blur instead
\begin{document}
  \begin{frame}
    \pause
    \lipsum[1]
  \end{frame}
\end{document}

However, I regularly have questions whose answer is covered and appears in the next overlay. People in the audience can then still see enough of the answer. I don't want to make covered elements invisible, because it helps me as a presenter to have an indication of how much more material there is on the slide. The degree of transparency can be controlled, but I don't think there is a level that solves my problem.

Hence my desire to blur covered elements. Is there a way to accomplish this in Beamer (easily)?

This question is about blurring words: How to blur a single word?, but I don't see how to use that in Beamer as an option to \setbeamercovered. Another blurring technique for text is discussed in this question: Blur the text so it's not readable, but again I don't know how to use it in Beamer.

Tom Verhoeff
  • 301

1 Answers1

2

Based on the fantastic answer https://topanswers.xyz/tex?q=6276#a6152 by @Skillmon, you could censor the still covered text:

% !TeX TS-program = lualatex

\documentclass{beamer}
\usepackage{lipsum}


\setbeamercovered{transparent}


\usepackage{lua-ul}
\usepackage{luacolor}


\ExplSyntaxOn
\makeatletter
\NewDocumentCommand \magic {O{\l__luaul_highlight_color_tl}} {
  @highLight [#1]
}
\makeatother
\ExplSyntaxOff


\makeatletter
\patchcmd{\beamer@startcovered}{\color{.}}{\color{.}\magic[.]}{}{}
\makeatother


\begin{document}
  \begin{frame}[t]
    \uncover<+->{}
    \uncover<+->{\lipsum[2]}
    \begin{itemize}[<+->]
    \item test
    \item test
    \end{itemize}
  \end{frame}
\end{document}

enter image description here

samcarter_is_at_topanswers.xyz
  • 158,329
  • Thank for the suggestion, but this fails to answer my question in a couple of ways: (1) If this is done to only a few words, then one can still see the `covered' answer; (2) it does not apply globally to all covered items; (3) when items are uncovered, they need to be normally visible. – Tom Verhoeff Sep 14 '23 at 15:33