我不太擅长使用 tikz。我想画一些类似的东西
到目前为止，通过查看我在网上找到的一些类似的解决方案，我可以做到这一点
使用以下代码
\begin{figure}
\centering
\begin{tikzpicture}
\coordinate(C2) at (0,0,0);
\node[cylinder,draw=black,thick,aspect=0.7,minimum height=5cm,minimum width=2cm,shape border rotate=0] (A) at ($(C2)-(0,0,0)$) {A};
\draw[dashed]
let \p1 = ($ (A.after bottom) - (A.before bottom) $),
\n1 = {0.5*veclen(\x1,\y1)-\pgflinewidth},
\p2 = ($ (A.bottom) - (A.after bottom)!0.5!(A.before bottom) $),
\n2 = {veclen(\x2,\y2)-\pgflinewidth}
in
([xshift=-\pgflinewidth] A.before bottom) arc [start angle=270, delta angle=180,
x radius=\n2, y radius=\n1];
\draw [<->] (A.before top) -- (A.after top) node [midway, above,fill=white] {$2a$};
\coordinate(C3) at (0,0);
\node [cylinder,draw=black,thick,aspect=0.7,minimum height=5cm,minimum width=2cm,shape border rotate=0] (B) at ($(C3)-(+2.7,0,7)$){3};
\draw[dashed]
let \p1 = ($ (B.after bottom) - (B.before bottom) $),
\n1 = {0.5*veclen(\x1,\y1)-\pgflinewidth},
\p2 = ($ (B.bottom) - (B.after bottom)!0.5!(B.before bottom) $),
\n2 = {veclen(\x2,\y2)-\pgflinewidth}
in
([xshift=-\pgflinewidth] B.before bottom) arc [start angle=270, delta angle=180,
x radius=\n2, y radius=\n1];
\draw [<->] (B.before top) -- (B.after top) node [midway, above,fill=white] {$2a$};
\draw[dashed](-3,0)to(3,0);
% \draw[dashed](7,0)to(9,0);
% \draw(0,-0.5)to(0,-1);
% \draw(7,-0.5)to(7,-1);
%\draw(0,-0.75)to(2,-0.75);
% \draw(7,-0.75)to(5,-0.75);
% \draw[dotted](2,-0.75)to(3.5,-0.75)node[above]{$\ell$}to(5,-0.75);
\end{tikzpicture}
\end{figure}
我需要说明的是，我“手动”将一个圆柱体放在另一个圆柱体上，但我真的不确定我是否知道它们是如何移动的。我如何才能清楚地定义这两个圆柱体的相对位置？有人知道如何添加垂直线“h”和水平线“z”吗？
答案1
您只需绘制直线和椭圆（或圆弧）。您还可以将圆柱体包含在循环中，\foreach这样您只需绘制一个。
像这样：
\documentclass[border=2mm]{standalone}
\usepackage {tikz}
\begin{document}
\begin{tikzpicture}[line cap=round,line join=round]
% dimensions
\def\a{1}
\def\h{4}
\def\z{3}
% cylinders
\foreach\i in {0,\h} % we draw the same figure at heights 0 and \h
{%
\draw[red] (-0.5*\z,\i) -- (-0.5*\a,\i); % axis
\draw[red,dashed] (-0.5*\a,\i) -- (\z,\i); % axis
\draw (\z,\i+\a) -- (0,\i+\a) arc (90:270:0.5*\a cm and \a cm) -- (\z,\i-\a) ;
\draw[dashed] (0,\i-\a) arc (-90:90:0.5*\a cm and \a cm);
\draw (\z,\i) ellipse (0.5*\a cm and \a cm);
\draw[red] (\z,\i) -- (1.5*\z,\i); % axis
\fill[red] (0,\i) circle (1pt);
\fill[red] (\z,\i) circle (1pt);
}
% auxiliary lines and labels
\draw[blue,dashed] (\z+0.2,\h+\a) -- (1.5*\z,\h+\a);
\draw[blue,dashed] (\z+0.2,-\a) -- (1.5*\z,-\a);
\draw[blue,dashed] (0,-\a-0.1) -- (0,-2*\a) node [below] {$z=0$};
\draw[blue,dashed] (\z,-\a-0.1) -- (\z,-2*\a) node [below] {$z=\ell$};;
\draw[blue,<->] (0,-2*\a+0.1) -- (\z,-2*\a+0.1) node [midway,below] {$z$};
\draw[blue,<->] (1.5*\z-0.1,-\a) -- (1.5*\z-0.1,0) node [midway,right] {$a$};
\draw[blue,<->] (1.5*\z-0.1,0) -- (1.5*\z-0.1,\h) node [midway,right] {$h$};
\draw[blue,<->] (1.5*\z-0.1,\h) -- (1.5*\z-0.1,\h+\a) node [midway,right] {$a$};
\end{tikzpicture}
\end{document}
将产生：
