我想画一个如下所示的 3 超链接（具有四个节点的超边）？我也附上了代码以供尝试

Question 1

您可以将star节点与一起使用rounded corners。尝试使用minimum size和star point ratio直到获得所需的结果。

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{shapes.geometric}

\tikzset{mynode/.style={draw, circle, fill=blue!40, minimum size=5mm}}

\begin{document}

\begin{tikzpicture}
\node[star, star points =4, star point ratio=1.7, draw, rounded corners=5mm, minimum size=3.2cm, fill=red!20] at (0,0) {};
\node[mynode] at (0,1){};
\node[mynode] at (1,0){};
\node[mynode] at (0,-1){};
\node[mynode] at (-1,0){};
\end{tikzpicture}

\end{document}

Answer

您可以将star节点与一起使用rounded corners。尝试使用minimum size和star point ratio直到获得所需的结果。

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{shapes.geometric}

\tikzset{mynode/.style={draw, circle, fill=blue!40, minimum size=5mm}}

\begin{document}

\begin{tikzpicture}
\node[star, star points =4, star point ratio=1.7, draw, rounded corners=5mm, minimum size=3.2cm, fill=red!20] at (0,0) {};
\node[mynode] at (0,1){};
\node[mynode] at (1,0){};
\node[mynode] at (0,-1){};
\node[mynode] at (-1,0){};
\end{tikzpicture}

\end{document}

Question 2

您发布的解决方案很好。

以下是替代方法的草图。它不一定能减少代码量，但可能会为您提供更多选择。主要思想：

使用fit库。接下来，定义Fit包含 4 个节点的节点，但不要绘制它。增加它的inner sep占比，因为我们想重用它的锚点。

        % ~~~ this nodes rectangle contains all 4 ~~~~~~~~~~
        \node[fit=(v1) (v2) (v3) (v4), inner sep=7mm] (Fit) {};

最后，使用您喜欢的绘图选项，使用锚点(Fit.west)等绘制路径。对于更复杂的黄色区域，您可能需要定义例如 4 个点，例如通过使用midway和相关（参见手册）。（例如，使用 4 个锚点进行不对称控制，在 v1-v4 周围形成一个不对称形状。） controls让您更好地控制摆动（贝塞尔曲线；是的，我简化了法语书写）。// 因为懒惰，出于演示目的，我只用绘制路径rounded corners。

        % ~~~ now draw a shape using its anchors ~~~~~
        %     refine this path as needed, e.g. by defining
        %     midway positions and use controls (Bezier) rather than angles
        \draw[fill=yellow!70,rounded corners=1cm] (Fit.west) -- (Fit.north) -- (Fit.east) -- (Fit.south) -- cycle;

一旦理解了指定的 4 个点之间的滑行线，这些控制就更容易控制：

虚线：使用参数 t 运行
绿色：已连接；再次运行
蓝色：互连
曲线上的点：蓝色互连线上的 t 值

% https://tex.stackexchange.com/questions/687673/i-want-to-draw-the-attached-figure-shown-below-i-have-also-included-the-code-fo

\documentclass[crop, tikz]{standalone}
\usepackage{tikz}
\usetikzlibrary{topaths,calc, backgrounds,fit}% <<<

\begin{document}

 \begin{tikzpicture} % one way to do it
    % Define the nodes and their positions
    \node[draw,circle,fill=blue!40] (v1) at (1,0) {$v_1$};
    \node[draw,circle,fill=blue!40] (v2) at (3,0) {$v_2$};
    \node[draw,circle,fill=blue!40] (v3) at (2,1.732) {$v_3$};
    \node[draw,circle,fill=blue!40] (v4) at (2,-1.732) {$v_4$};

    \begin{pgfonlayer}{background}
        % ~~~ this nodes rectangle contains all 4 ~~~~~~~~~~
        \node[fit=(v1) (v2) (v3) (v4), inner sep=7mm] (Fit) {};
        % ~~~ now draw a shape using its anchors ~~~~~
        %     refine this path as needed, e.g. by defining
        %     midway positions and use controls (Bezier) rather than angles
        \draw[fill=yellow!70,rounded corners=1cm] (Fit.west) -- (Fit.north) -- (Fit.east) -- (Fit.south) -- cycle;
    \end{pgfonlayer}    
    
 \end{tikzpicture}


 \begin{tikzpicture} % posted solution
    % Define the nodes and their positions
    \node[draw,circle,fill=blue!40] (v1) at (1,0) {$v_1$};
    \node[draw,circle,fill=blue!40] (v2) at (3,0) {$v_2$};
    \node[draw,circle,fill=blue!40] (v3) at (2,1.732) {$v_3$};
    \node[draw,circle,fill=blue!40] (v4) at (2,-1.732) {$v_4$};

    % Draw the shape and fill it
    \begin{pgfonlayer}{background}
        \filldraw[fill=yellow!70] ($(v1) + (-0.5,0)$)
                to[out=90,in=180] ($(v1) + (0.5, 0.5)$)
                to[out=0,in=270] ($(v3) + (-0.5, 0)$)
                to[out=90,in=180] ($(v3) + (0, 0.5)$)
                to[out=0,in=90] ($(v3) + (0.5, 0.0)$)
                to[out=270,in=180] ($(v2) + (-0.5, 0.5)$)
                to[out=0,in=90] ($(v2) + (0.5, 0)$)
                to[out=270,in=0] ($(v2) + (-0.5, -0.5)$)
                to[out=180,in=90] ($(v4) + (0.5, 0.0)$)
                to[out=270,in=0] ($(v4) + (0.0, -0.5)$)
                to[out=180,in=270] ($(v4) + (-0.5, 0.0)$)
                to[out=90,in=0] ($(v1) + (0.5, -0.5)$)
                to[out=180,in=270] ($(v1) + (-0.5,0)$);                               
    \end{pgfonlayer}
 \end{tikzpicture}

\end{document}

附言：作为附加内容，这里有一种明确引入 4 个坐标的方法。

如代码所示，现在有 4 个参数可以改变外观：

参数1：极坐标的角度
参数2：极坐标半径
参数3：此节点内部分离(Fit)
参数4：圆角半径

虽然我很懒，但是我用了一个\foreach循环来定义 4 个角度和一个计数器\i，这有助于命名坐标名称。

 % ~~~ defining 4 extra points ~~~~~~~~~
    \foreach \a [count=\i] in {50, 140, 230, 310}% <<< Parameter 1: angles of polar coordinates
        \coordinate (c\i) at (\a:1.1);% <<<< Parameter 2: radius of polar coordinates

 \begin{tikzpicture} % second way to do it
    % Define the nodes and their positions
    % ~~~ shifted to the left ~~~ <<<<<<<<<<<<<<<<
    \node[draw,circle,fill=blue!40] (v1) at (-1,0) {$v_1$};
    \node[draw,circle,fill=blue!40] (v2) at (1,0) {$v_2$};
    \node[draw,circle,fill=blue!40] (v3) at (0,1.732) {$v_3$};
    \node[draw,circle,fill=blue!40] (v4) at (0,-1.732) {$v_4$};
    
    % ~~~ defining 4 extra points ~~~~~~~~~
    \foreach \a [count=\i] in {50, 140, 230, 310}% <<< Parameter 1: angles of polar coordinates
        \coordinate (c\i) at (\a:1.1);% <<<< Parameter 2: radius of polar coordinates

    \begin{pgfonlayer}{background}
        % ~~~ this nodes rectangle contains all 4 ~~~~~~~~~~
        \node[fit=(v1) (v2) (v3) (v4), inner sep=13mm] (Fit) {};% <<< Parameter 3: this nodes inner separation
        % ~~~ now draw a shape using its anchors ~~~~~
        %     refine this path as needed, e.g. by defining
        %     midway positions and use controls (Bezier) rather than angles
        \draw[fill=yellow!70,rounded corners=10mm] % <<< Parameter 4: radius of rounded corners
                    (Fit.west) -- (c2) -- (Fit.north) -- (c1) -- 
                    (Fit.east) -- (c4) --  (Fit.south) -- (c3) -- cycle;
        % ~~~ just to show the 4 extra coordinates ~~~
        \draw[fill=orange!70] (c2) -- (c1) -- (c4)  -- (c3) -- cycle;       
    \end{pgfonlayer}        
 \end{tikzpicture}

Answer