纸板制成的盒子

Question

让我们从第二张图片开始。

在这里我定义了一个\tikzrectwithsquares命令，它接受X值，宽度和高度并据此构造矩形。

首先，将定义各种坐标（并非所有坐标都会用到）。这些是矩形的角以及该加号形内部多边形的所有点。然后可以使用这些额外的坐标和-|/|-路径操作来勾勒出这个加号形的轮廓并填充它，但不填充角落中的四个正方形。

键x和y用于缩放坐标系，以便我们可以在绘图代码中直接使用36和。24

3D图片实际上更容易使用3d view钥匙。这里我使用 −60° 的方位角和 20° 的悬浮角来将矩形旋转得更像横向。

如果您不想让前面后面的侧面透光，请将fill opacity = .5其移除rf/front。

我们可以使用3d库的canvas is plane …键，但使用这些简单的矩形，直接使用角几乎更容易。

代码

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta, perspective}
\makeatletter
\tikzset{scale xyz/.code={%
  \pgfmathparse{#1}%
  \pgf@xx=\pgfmathresult\pgf@xx \pgf@xy=\pgfmathresult\pgf@xy
  \pgf@yx=\pgfmathresult\pgf@yx \pgf@yy=\pgfmathresult\pgf@yy
  \pgf@zx=\pgfmathresult\pgf@zx \pgf@zy=\pgfmathresult\pgf@zy}}
\makeatother
\tikzset{
  % rectangle with squares:
  rws/picture/.style={
    x=+.16667cm, y=+.16667cm, line cap=round, line join=round,
    magenta, >={Straight Barb[angle=60:3pt 2]},
    xy shift/.style 2 args={shift={({##1(#1)},{##2(#1)})}}},
  rws/make extra coordinates/.style n args={3}{
    label={[shape=coordinate,xy shift={#1}{#2},name=\tikzlastnode']center:},
    label={[shape=coordinate,xy shift={#1}{0*},name=\tikzlastnode-x]center:},
    label={[shape=coordinate,xy shift={0*}{#2},name=\tikzlastnode-y]center:}},
  %%% drawing styles:
  rws/wo x/.style={fill=magenta!15},
  rws/with x/.style={auto=right, draw, dashed},
  rws/rect/.style={draw, thick},
  rws/measure/.style={black, nodes={fill=white}, |<->|},
  % rectangle folded:
  rf/picture/.style={
    3d view={-60}{20}, scale xyz=1/6,
    line cap=round, line join=round, magenta,
    >={Straight Barb[angle=60:3pt 2]},},
  rf/make extra coordinate/.style={
    label={[shape=coordinate,shift={(0,0,{#1})},name=\tikzlastnode']center:}},
  %%% drawing styles:
  rf/bottom/.style={draw, fill=magenta!15},
  rf/back/.style={rf/bottom},
  rf/front/.style={rf/bottom, fill opacity=.5},
}
\newcommand*\tikzrectwithsquares[4][]{% #2 = x, #3 = w, #4 = h
  \begin{tikzpicture}[rws/picture={#2},#1]
  \coordinate[rws/make extra coordinates=++] (BL) at (0,0)
   coordinate[rws/make extra coordinates=-+] (BR) at (right:{#3})
   coordinate[rws/make extra coordinates=--] (TR) at ({#3},{#4})
   coordinate[rws/make extra coordinates=+-] (TL) at (up:{#4});
  \path[rws/wo x](BL-x) -| (BR') -| (TR-y) -| (TR-x) -| (TL') -| (BL-y) -| cycle;
  \path[rws/with x] foreach[count=\rot from 0] \corner in {BL, BR, TR, TL}{
      [rotate=\rot*90] (\corner) -| node [near end]{$x$} (\corner')
                                 -| node [near start]{$x$} cycle          };
  \draw[rws/rect] (BL) rectangle (TR);
  \path[rws/measure] ([xshift=+-5mm]BL) edge node{$#4$} ([xshift=+-5mm]TL)
                     ([yshift=+-5mm]BL) edge node{$#3$} ([yshift=+-5mm]BR);
  \end{tikzpicture}}
\newcommand*\tikzrectfolded[4][]{% #2 = x, #3 = w, #4 = h
  \begin{tikzpicture}[rf/picture,#1]
  \coordinate[rf/make extra coordinate={#2}] (BL) at (0,0,0)
   coordinate[rf/make extra coordinate={#2}] (BR) at ({#3},0,0)
   coordinate[rf/make extra coordinate={#2}] (TR) at ({#3},{#4},0)
   coordinate[rf/make extra coordinate={#2}] (TL) at (0,{#4},0);
   \path[rf/back]   (TL) -- (TR) -- (TR') -- (TL') -- cycle;
   \path[rf/back]   (TR) -- (BR) -- (BR') -- (TR') -- cycle;
   \path[rf/bottom] (BL) -- (BR) -- (TR)  -- (TL)  -- cycle;
   \path[rf/front]  (TL) -- (BL) -- (BL') -- (TL') -- cycle;
   \path[rf/front]  (BL) -- (BR) -- (BR') -- (BL') -- cycle;
  \end{tikzpicture}}
\begin{document}
\tikzrectwithsquares[baseline=0]{4}{36}{24}
\tikzrectfolded     [baseline=0]{4}{36}{24}
\end{document}
\tikzset{debug node/.style={append after command={
  \pgfextra\begingroup\pgftransformreset
    \pgftext[at=\pgfpointanchor{\tikzlastnode}{north},bottom]%
      {\tiny\color{magenta}\tikzlastnode}\endgroup\endpgfextra}}}

输出

Answer 1