3D 图形中的尺寸线

Question

我首先从你的问题开始，修改尺寸代码或如何使用它在 3D 中工作最简单的方法是什么？ 我建议进行两项改变以实现您的目标：

对 2D 绘图使用相同的代码
3D 绘图中，尺寸元素位于所需平面中。

的初始代码indicate dimensions相对于要测量的线段方向顺时针旋转 90 度。这在 2D 绘图中没有问题，但在 3D 中则不行（因为计算pgf使用的是 2D 点，因此角度始终被视为 90 度屏幕上）。

答案。 为了解决这个问题，我引入了一个 pgf 键，angleshift，默认值为 0。在 3D 绘图时，只需修改其值即可（例如在scope准备调用的命令中indicate dimensions）。angleshift执行逆时针旋转。

现在，关于代码中的修改：angleshift用于修改

转弯角度
打印参数的文本的方向（将其包含在所需的平面中）
箭头的尖端（使它们属于所需的平面，如上例中的 3）。

平行六面体绘图

代码。 这主要是您的代码，并带有我所描述的小修改。它们以标记% modification <something>。

\documentclass[11pt, margin=1cm]{standalone}
\usepackage{xparse}
\usepackage{tikz}
\usetikzlibrary{3d}

%% ---------------------------------------------------------------------
%% https://tex.stackexchange.com/a/468144/4301
\usetikzlibrary{calc, decorations.pathreplacing, arrows.meta}
\newif\ifdrawdimlineleft
\newif\ifdrawdimlineright

\pgfkeys{/tikz/.cd,  % modification angleshift definition
  angleshift/.store in=\angleshift,
  angleshift=0
}
\tikzset{%
  dimlabel distance/.initial=5mm,
  vertical lines extend/.initial=5mm,
  vertical dim line/.style={gray, thin},
  dim arrow line/.style={%  % modification tip
    arrows={latex[slant={-sin(\angleshift)}]-latex[slant={-sin(\angleshift)}]},
    thin
  },
  dim label/.style={},
  left dimline/.is if=drawdimlineleft,
  left dimline=true,
  right dimline/.is if=drawdimlineright,
  right dimline=true,
  indicate dimensions/.style={%
    decorate, decoration={%
      show path construction,
      lineto code={%
        \draw[dim arrow line]  % modification arrow line 
        ($(\tikzinputsegmentfirst)!\pgfkeysvalueof{/tikz/dimlabel distance}!
        {-90+\angleshift}:(\tikzinputsegmentlast) $)
        -- ($ (\tikzinputsegmentlast)!\pgfkeysvalueof{/tikz/dimlabel distance}!
        {90+\angleshift}:(\tikzinputsegmentfirst) $)
        \ifx#1\empty
        \else  % modification text
        node[midway, fill=white, dim label,
        sloped, xslant={-sin(\angleshift)}, scale=.8]{#1}
        \fi;
        \ifdrawdimlineleft  % modification vertical dim line
        \draw[vertical dim line] (\tikzinputsegmentfirst) -- 
        ($ (\tikzinputsegmentfirst)!\pgfkeysvalueof{/tikz/vertical lines
          extend}!{-90+\angleshift}:(\tikzinputsegmentlast) $);
        \fi
        \ifdrawdimlineright
        \draw[vertical dim line] (\tikzinputsegmentlast) -- 
        ($ (\tikzinputsegmentlast)!\pgfkeysvalueof{/tikz/vertical
          lines extend}!{90+\angleshift}:(\tikzinputsegmentfirst) $);
        \fi 
      }
    }
  }
}

%% ---------------------------------------------------------------------

\NewDocumentCommand{\DrawCoordinateGrid}{O{} m m m m m m}{%
  \def\XGridMin{#2}
  \def\XGridMax{#3}
  \def\YGridMin{#4}
  \def\YGridMax{#5}
  \def\ZGridMin{#6}
  \def\ZGridMax{#7}
  % 
  \begin{scope}[canvas is xy plane at z=0, ultra thin, gray!75]
    \draw [#1] (\XGridMin,\YGridMin) grid (\XGridMax,\YGridMax);
  \end{scope}
  \begin{scope}[canvas is yz plane at x=0, ultra thin, gray!75]
    \draw [#1] (\YGridMin,\ZGridMin) grid (\YGridMax,\ZGridMax);
  \end{scope}
  \begin{scope}[canvas is xz plane at y=0, ultra thin, gray!75]
    \draw [#1] (\XGridMin,\ZGridMin) grid (\XGridMax,\ZGridMax);
  \end{scope}
}

\NewDocumentCommand{\DrawCoordinateAxis}{O{} m m m m m m}{%
  \def\XAxisMin{#2}
  \def\XAxisMax{#3}
  \def\YAxisMin{#4}
  \def\YAxisMax{#5}
  \def\ZAxisMin{#6}
  \def\ZAxisMax{#7}
  % 
  \begin{scope}[thin, gray, -latex]
    \draw [#1] (\XAxisMin,0,0) -- (\XAxisMax,0,0) node [below left] {$x$};
    \draw [#1] (0,\YAxisMin,0) -- (0,\YAxisMax,0) node [right] {$y$};
    \draw [#1] (0,0,\ZAxisMin) -- (0,0,\ZAxisMax) node [above] {$z$};
  \end{scope}
}%

\newcommand*\Width{2.5}%
\newcommand*\Depth{4.5}%
\newcommand*\Height{2.0}%
\tikzset{Line Style/.style={draw=brown, ultra thick, join=round}}
\begin{document}

\begin{tikzpicture}[
  x={(-0.5cm,-0.5cm)}, 
  y={(0.9659cm,-0.25882cm)}, 
  z={(0cm,1cm)}]
  
  \coordinate (O) at (0,0,0);
  %% ---------------------------------------------- yz plane at x=0
  \coordinate (A) at (0,\Width,0);
  \coordinate (B) at (0,\Width,\Height);
  \coordinate (C) at (0,0,\Height);
  %% ---------------------------------------------- yz plane at x=\Depth
  \coordinate (D) at (\Depth,0,0);
  \coordinate (E) at (\Depth,\Width,0);
  \coordinate (F) at (\Depth,\Width,\Height);
  \coordinate (G) at (\Depth,0,\Height);
  
  \DrawCoordinateGrid{0}{6}{0}{4}{0}{3}
  \DrawCoordinateAxis[thick, black]{0}{6.5}{0}{4.5}{0}{3.5}
  
  %% ------------------------------------ Draw the rectangular prism
  \draw [Line Style] (O) -- (A) -- (B) -- (C) -- cycle;% yz plane at x=0
  \draw [Line Style] (D) -- (E) -- (F) -- (G) -- cycle;% yz plane at x=\Depth
  \draw [Line Style] (O) -- (D) -- (G) -- (C) -- cycle;% xz plane at y=0
  \draw [Line Style] (A) -- (E) -- (F) -- (B) -- cycle;% xz plane at y=\Width
  
  % modification angleshift
  \path [angleshift=30, blue, indicate dimensions={$2$}, inner sep=2pt] 
  (C) -- (G);
  
  %% Following is for debugging purposes so you can see where the points are
  %% These are last so that they show up on top
  \foreach \xy in {O, A, B, C, D, E, F, G}{
    \node at (\xy) {\tiny\xy};
  }    
\end{tikzpicture}
\end{document}

Answer 1