Two tikzpictures in minipages have overlapped caption

Question

I'm trying to put two tikzpictures in two minipages, but their caption are overlapped. Here the code I'm using.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[a4paper,top=2.5cm,bottom=2.50cm,left=3.00cm,right=3.00cm]{geometry}


 \usepackage{float}
    \usepackage{wrapfig}
    \usepackage{amsmath,amssymb,commath}
    \usepackage{caption}    
    \usepackage{tikz}
    \usepackage[RPvoltages]{circuitikz}
    \usepackage{tkz-euclide}
    \usepackage{subcaption}
  
\captionsetup {
       format=plain,
       width=0.80\textwidth,
       font=normal, 
       labelfont=bf,
       figurename = Fig. ,
       tablename = Tab.
    }

    \title{\Huge{\textbf{Test}}}
    \author{me}
    \date{}
    
    \begin{document}
    
    \maketitle
    
    \begin{figure}
\centering
        \begin{minipage}{0.4\textwidth}
            \centering
            \begin{tikzpicture}
                \centering
                \draw [<->,thick] (0,2.8) node (yaxis) [left] {$t$}
                    |- (2.8,0) node (xaxis) [right] {$x$};
                \draw[thick]
                    (0,0) -- (0,-2.8)
                    (0,0) -- (-2.8,0);
                \draw[green, ultra thick] (0,-2.90) -- (0,2.90);
                \draw[dashed] 
                    (0,2.90) -- (0,2.95)
                    (0,-2.90) -- (0,-2.95);
            \end{tikzpicture}
            \captionof{figure}{Worldline of a static point-like source}
            \label{fig:static_source}
        \end{minipage}
        \begin{minipage}{0.4\textwidth}
            \centering
            \begin{tikzpicture}
                \draw [<->,thick] (0,2.8) node (yaxis) [left] {$t$}
                    |- (2.8,0) node (xaxis) [right] {$x$};
                \draw[thick]
                    (0,0) -- (0,-2.8)
                    (0,0) -- (-2.8,0);
                \node[mark size = 3pt, green] at (0,0) {\pgfuseplotmark{*}};
                \draw[dashed] 
                    (0,2.90) -- (0,2.95)
                    (0,-2.90) -- (0,-2.95);
            \end{tikzpicture}
            \captionof{figure}{Worldline of an instantaneous point-like source}
            \label{fig:inst_source}
        \end{minipage}
    \end{figure}
    
    \end{document}

Can someone help me? I see that without the caption setup it works good.

Answer 1

• As I mentioned in comment, problem is your caption set up. If you like to have, that the caption width id 0.8 width of environment, where it is, than the width you need to setup in this environment.
• In your case you not need to use \captionof since captions are inside figure float.
• Remove command \centering inside of tikzpicture (it's no harm, nor it has any benefit)
• Using \hfill between minipages will push them apart so that all horisontal spaces around them will be equal.

A possible MWE (in which I removed everything that has nothing to do with your problem) is:

\documentclass{article}
\usepackage[a4paper,
            hmargin=3cm, vmargin=2.5cm]{geometry}
\usepackage[T1]{fontenc}
\usepackage{caption,subcaption}
\captionsetup{ format=plain,
               labelfont=bf,
               figurename = Fig. ,
               tablename = Tab.}
\usepackage{tikz}

\begin{document}
\begin{figure}
\centering
    \begin{minipage}{0.4\textwidth}
        \centering
        \begin{tikzpicture}
            \draw [<->,thick] (0,2.8) node (yaxis) [left] {$t$}
                |- (2.8,0) node (xaxis) [right] {$x$};
            \draw[thick]
                (0,0) -- (0,-2.8)
                (0,0) -- (-2.8,0);
            \draw[green, ultra thick] (0,-2.90) -- (0,2.90);
            \draw[dashed]
                (0,2.90) -- (0,2.95)
                (0,-2.90) -- (0,-2.95);
        \end{tikzpicture}
        \captionsetup{width=0.80\textwidth}
        \caption{Worldline of a static point-like source}
        \label{fig:static_source}
    \end{minipage}\hfil
    \begin{minipage}{0.4\textwidth}
        \centering
        \begin{tikzpicture}
            \draw [<->,thick] (0,2.8) node (yaxis) [left] {$t$}
                |- (2.8,0) node (xaxis) [right] {$x$};
            \draw[thick]
                (0,0) -- (0,-2.8)
                (0,0) -- (-2.8,0);
            \node[mark size = 3pt, green] at (0,0) {\pgfuseplotmark{*}};
            \draw[dashed]
                (0,2.90) -- (0,2.95)
                (0,-2.90) -- (0,-2.95);
        \end{tikzpicture}
        \captionsetup{width=0.80\textwidth}
        \caption{Worldline of an instantaneous point-like source}
        \label{fig:inst_source}
    \end{minipage}
\end{figure}
\end{document}

Answer 2

Just introduce \hspace{2pc} tag will add more horizontal space between the images, and the MWE is:

    \documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[a4paper,top=2.5cm,bottom=2.50cm,left=3.00cm,right=3.00cm]{geometry}


    \usepackage{float}
    \usepackage{wrapfig}
    \usepackage{amsmath,amssymb,commath}
    \usepackage{caption}    
    \usepackage{tikz}
    \usepackage[RPvoltages]{circuitikz}
    \usepackage{tkz-euclide}
    \usepackage{subcaption}
    

    \title{\Huge{\textbf{Test}}}
    \author{me}
    \date{}
    
    \begin{document}
    
    \maketitle
    
    \begin{figure}
        \begin{minipage}{0.4\textwidth}
            \centering
            \begin{tikzpicture}
                \centering
                \draw [<->,thick] (0,2.8) node (yaxis) [left] {$t$}
                    |- (2.8,0) node (xaxis) [right] {$x$};
                \draw[thick]
                    (0,0) -- (0,-2.8)
                    (0,0) -- (-2.8,0);
                \draw[green, ultra thick] (0,-2.90) -- (0,2.90);
                \draw[dashed] 
                    (0,2.90) -- (0,2.95)
                    (0,-2.90) -- (0,-2.95);
            \end{tikzpicture}
            \captionof{figure}{Worldline of a static point-like source}
            \label{fig:static_source}
        \end{minipage}\hspace{2pc}
        \begin{minipage}{0.4\textwidth}
            \centering
            \begin{tikzpicture}
                \draw [<->,thick] (0,2.8) node (yaxis) [left] {$t$}
                    |- (2.8,0) node (xaxis) [right] {$x$};
                \draw[thick]
                    (0,0) -- (0,-2.8)
                    (0,0) -- (-2.8,0);
                \node[mark size = 3pt, green] at (0,0) {\pgfuseplotmark{*}};
                \draw[dashed] 
                    (0,2.90) -- (0,2.95)
                    (0,-2.90) -- (0,-2.95);
            \end{tikzpicture}
            \captionof{figure}{Worldline of an instantaneous point-like source}
            \label{fig:inst_source}
        \end{minipage}
    \end{figure}
    
    \end{document}

OUTPUT

Please correct me if my understanding is not correct....