[Tex/LaTex] Logo on the bottom of title page – beamer – metropolis theme

Question

I'm trying to add three logos on the title page of my presentation. I'm using Beamer and the metropolis theme.
I've tried to use the \titlegraphic command but the picture appears at the top left of the slide. So I modified the .sty file using hspace and vspace but I would like to know if there is a better way to do so. Indeed, what I did is OK for this presentation but not re-usable for another one with another logo of different size. Thanks.

Answer 1

You could define your own title page with the titlegraphic at the bottom:

\documentclass{beamer}
\usetheme{metropolis}

\titlegraphic{%
    \includegraphics[width=.2\textwidth]{example-image-a}\hfill
  \includegraphics[width=.2\textwidth]{example-image-b}\hfill
  \includegraphics[width=.2\textwidth]{example-image-c}
}

\makeatletter
\setbeamertemplate{title page}{
  \begin{minipage}[b][\paperheight]{\textwidth}
    \vfill%
    \ifx\inserttitle\@empty\else\usebeamertemplate*{title}\fi
    \ifx\insertsubtitle\@empty\else\usebeamertemplate*{subtitle}\fi
    \usebeamertemplate*{title separator}
    \ifx\beamer@shortauthor\@empty\else\usebeamertemplate*{author}\fi
    \ifx\insertdate\@empty\else\usebeamertemplate*{date}\fi
    \ifx\insertinstitute\@empty\else\usebeamertemplate*{institute}\fi
    \vfill
    \ifx\inserttitlegraphic\@empty\else\inserttitlegraphic\fi
    \vspace*{1cm}
  \end{minipage}
}
\makeatother

\begin{document}

\begin{frame}
    \titlepage
\end{frame} 

\end{document}