无法将 tikz 正确定位在 beamer 背景上

Question

我正在尝试beamer使用该pgfornaments包制作自定义背景。尽管指定了坐标，但我似乎无法定位图像。

这是我的 MWE：

\documentclass[xcolor=dvipsnames]{beamer}
\usepackage[sfdefault]{atkinson}
\usepackage{microtype}
\usepackage{textpos}
\usepackage{tikz}
\usepackage{pgfornament}

\beamertemplatenavigationsymbolsempty

\title{The Patience Test Study}
\author[TeX User]{TeX User}
\institute{University of Kyoto}

%%%Background
\setbeamertemplate{background}{%
\begin{tikzpicture}[remember picture, absolute]
\foreach \i in {4,5,6,...,10}
\node[] at (\i,0) {\pgfornament[width=1cm]{70}};
%
\foreach \i in {4,5,6,...,10}
\node[] at (\i,9) {\pgfornament[width=1cm]{70}};
\end{tikzpicture}
}%


%%%Titlepage
\makeatletter
\setbeamertemplate{title page}{
    \centering
    \vfill
      \usebeamerfont{title}\inserttitle\par%
      \ifx\insertsubtitle\@empty%
      \else%
        \vskip0.1em%
        {\usebeamerfont{subtitle}\usebeamercolor[fg]{subtitle}\insertsubtitle\par}%
      \fi%
      \vskip-0.4em\par
      \begin{tikzpicture}
      \pgfornament[width=1cm]{75};
      \end{tikzpicture}
    \vskip0.5em\par
      \usebeamerfont{author}\small\insertauthor\par
      \vskip1.2em%
      \usebeamerfont{institute}\insertinstitute\par
      \vskip0.1em%
    {\usebeamercolor[fg]{titlegraphic}\inserttitlegraphic\par}
    \vskip0.1em%
    {\scriptsize{\usebeamerfont{date}\insertdate}}
    \vfill
}
\makeatother

\begin{document}

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


\begin{frame}
\frametitle{Introduction}
\framesubtitle{Basic research question}

\end{frame}

\end{document}

以下是标题页的相应输出：

在此示例中，尽管在 tikz 节点中声明了绝对坐标，但我无法将装饰物集中起来。我该如何使用此beamer模板上的绝对位置来定位元素。

Answer 1

我喜欢用这个小技巧https://topanswers.xyz/tex?q=1989相对于页面定位 tikzpicture。这会将图片的原点放置在页面的南下角，您可以通过将节点从 -x 放置到 x 来对称排列节点。

\documentclass[xcolor=dvipsnames]{beamer}
\usepackage[sfdefault]{atkinson}
\usepackage{microtype}
\usepackage{textpos}
\usepackage{tikz}
\usepackage{pgfornament}

\beamertemplatenavigationsymbolsempty

\title{The Patience Test Study}
\author[TeX User]{TeX User}
\institute{University of Kyoto}

% trick taken from https://topanswers.xyz/tex?q=1989
\tikzset{
    position in page centre/.style={
        shift={(current page.south)}
    },
}

%%%Background
\setbeamertemplate{background}{%
\begin{tikzpicture}[remember picture,overlay,position in page centre]
\foreach \i in {-4,...,4}
\node[] at (\i,0.5) {\pgfornament[width=1cm]{70}};
%
\foreach \i in {-4,...,4}
\node[] at (\i,9) {\pgfornament[width=1cm]{70}};
\end{tikzpicture}
}%


%%%Titlepage
\makeatletter
\setbeamertemplate{title page}{
    \centering
    \vfill
      \usebeamerfont{title}\inserttitle\par%
      \ifx\insertsubtitle\@empty%
      \else%
        \vskip0.1em%
        {\usebeamerfont{subtitle}\usebeamercolor[fg]{subtitle}\insertsubtitle\par}%
      \fi%
      \vskip-0.4em\par
      \begin{tikzpicture}
      \pgfornament[width=1cm]{75};
      \end{tikzpicture}
    \vskip0.5em\par
      \usebeamerfont{author}\small\insertauthor\par
      \vskip1.2em%
      \usebeamerfont{institute}\insertinstitute\par
      \vskip0.1em%
    {\usebeamercolor[fg]{titlegraphic}\inserttitlegraphic\par}
    \vskip0.1em%
    {\scriptsize{\usebeamerfont{date}\insertdate}}
    \vfill
}
\makeatother

\begin{document}

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


\begin{frame}
\frametitle{Introduction}
\framesubtitle{Basic research question}

\end{frame}

\end{document}