Tikz 绘制没有边缘的轮廓，并填充

Question

我想绘制两个波浪形轮廓，如下图所示，并填充中间的区域。我尝试了以下代码，但它在右侧产生了不想要的黑色垂直边缘。我该如何去除它？

\documentclass[tikz]{standalone}
\begin{document}
\begin{tikzpicture}
  \useasboundingbox (-1,-1) rectangle (6,2);
  \draw[fill=black!10] (0,1) to[out=0,in=180] ++(5,-0.6) -- ++(0,0.6) to[out=180,in=0] ++(-5,-0.6);
\end{tikzpicture}
\end{document}

我也尝试删除第五行--之间的++(5,-0.6)和++(0,0.6)，它不会画出不需要的边缘，但它会弄乱填充。

\documentclass[tikz]{standalone}
\begin{document}
\begin{tikzpicture}
   \useasboundingbox (-1,-1) rectangle (6,2);
   \draw[fill=black!10] (0,1) to[out=0,in=180] ++(5,-0.6) ++(0,0.6) to[out=180,in=0] ++(-5,-0.6);
\end{tikzpicture}
\end{document}

Answer 1

快速而粗略：先填充区域，然后绘制您想要绘制的内容。关闭部分路径的绘制并不容易（但可以做到，但需要付出更多努力）。

\documentclass[tikz]{standalone}
\begin{document}
\begin{tikzpicture}
  \useasboundingbox (-1,-1) rectangle (6,2);
  \path[fill=black!10] (0,1) to[out=0,in=180] ++(5,-0.6) -- ++(0,0.6) to[out=180,in=0] ++(-5,-0.6);
  \draw (0,1) to[out=0,in=180] ++(5,-0.6)++(0,0.6) to[out=180,in=0] ++(-5,-0.6);
\end{tikzpicture}
\end{document}

你能打开或关闭路径例如使用这个答案。

\documentclass[tikz]{standalone}
\pgfkeys{tikz/.cd,
edge options/.code={\tikzset{edge style/.style={#1}}},
}
\begin{document}
\begin{tikzpicture}[every edge/.append code = {% https://tex.stackexchange.com/a/396092/121799 
    \global\let\currenttarget\tikztotarget % save \tikztotarget in a global variable
    \pgfkeysalso{append after command={to[edge style] (\currenttarget)}}},
every edge/.append style={edge style}   ] 
  \useasboundingbox (-1,-1) rectangle (6,2);
  \path[fill=black!10] 
  (0,1) [edge options={out=0,in=180,draw=black}]  edge  ++(5,-0.6) 
  -- ++(0,0.6) 
  [edge options={out=180,in=0,draw=black}] edge ++(-5,-0.6);
\end{tikzpicture}
\end{document}

Answer 2

使用 TikZ 库pgfplots.fillbetween

\documentclass[margin=3mm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.16}
\usetikzlibrary{pgfplots.fillbetween}

\begin{document}
    \begin{tikzpicture}
\draw[name path=A]  (0, 0.3) to [out=0,in=180] ++(5,-0.6);
\draw[name path=B]  (0,-0.3) to [out=0,in=180] ++(5, 0.6);
\tikzfillbetween[of=A and B] {fill=gray!30};
    \end{tikzpicture}
\end{document}

Answer 3

为了比较，元帖子，其中填充和绘制是分开的，并且您可以直接连接路径变量。

\documentclass[border=5mm]{standalone}
\usepackage{luatex85}
\usepackage{luamplib}
\begin{document}
\begin{mplibcode}
beginfig(1);
    z0 = (-72, 8.5);

    path A, B;
    A = z0 {right} .. {right} z0 rotated 180;
    B = A reflectedabout(up, down);

    fill A -- B -- cycle withcolor 7/8[blue, white];
    draw A;
    draw B;
endfig;
\end{mplibcode}
\end{document}

（编译为lualatex...）