如何修改此 TikZ 代码以在其他位置绘制

Question 1

我决定使用重新绘制图片，而不是纠缠于现有代码tikz-3dplot。

arrows.meta为了方便起见，我使用和使用对箭头进行了一些调整backgrounds。代码应该更容易理解和修改。至少理论上如此。当然，你的公里数可能会有所不同。

唯一的麻烦在于，你需要在脑子里交换轴y和z轴，因为tikz-3dplot你真的非常希望z轴在页面上向上或向下移动。为了帮助我做到这一点，我使用了

\draw [help lines] (-2,0,0) -- (2,0,0) node[anchor=north west]{$x$} (0,0,0) -- (0,7,0) node[anchor=north east]{$y$} (0,0,0) -- (0,0,2) node[anchor=north]{$z$} (-2,7,0) -- (2,7,0);

在绘制图片时，然后对此进行评论，并在最后添加实际的轴标签等。

我也用过

\foreach \i in {a,b,c,d} \node [red, font=\scriptsize] at (\i) {\i};

来追踪我在灰色框的每个角落放置的坐标。

这两种设备都保留了下来，在下面的代码中进行了注释以供参考。要使用它们，您可能还需要注释实际的轴和标签以避免混淆。也就是说，注释以下行

  \draw [thick, ->, every node/.style={font=\footnotesize, inner sep=0pt}] (o) node [anchor=north west] {$F_c$} (o) edge node [pos=1, anchor=north east] {$z_c$} ++(0,1,0) edge node [pos=1, anchor=north] {$y_c$} ++(0,0,1) -- ++(1,0,0) node [anchor=north west] {$x_c$};

其余部分相对简单，尽管有点乏味。毫无疑问，它可以变得更高效，但我认为，尽管如此，它还是比原始代码高效得多。

结果不是像素相同的，因此可能需要稍微调整以适合您的目的、偏好和/或品味。

代码：

% ail-wneud y llun o gwestiwn perr0: http://tex.stackexchange.com/q/96074/
% côd newydd
\documentclass[border=10pt,multi,tikz]{standalone}
\usepackage{tikz-3dplot}
\usetikzlibrary{calc,arrows.meta,positioning,backgrounds}
\begin{document}
\tdplotsetmaincoords{-60}{-35}
\begin{tikzpicture}
  [
    tdplot_main_coords,
    >=Stealth,
    my dashed/.style={dashed, thick, ->, shorten >=-15pt, shorten <=-15pt, every node/.append style={font=\footnotesize}},
    my box/.style={thin, gray!70},
    my blue/.style={blue, line cap=round, -{Triangle[width=3*#1]}, line width=#1, shorten >=#1*1.75pt, every node/.append style={fill, circle, inner sep=0pt, minimum size=#1*3.5pt, anchor=center, outer sep=0pt}},
    my label/.append style={midway, font=\scriptsize},
    my vectors/.style={green!50!black, {Stealth[scale=.75]}-{Stealth[scale=.75]}},
    my red/.style={thick, red, line cap=round},
    my grey/.style={gray!70},
    description/.style={draw=gray!70, thick, line cap=round, every node/.style={align=center, font=\scriptsize\sffamily, anchor=north}},
  ]
%   \draw [help lines] (-2,0,0) -- (2,0,0) node[anchor=north west]{$x$} (0,0,0) -- (0,7,0) node[anchor=north east]{$y$} (0,0,0) -- (0,0,2) node[anchor=north]{$z$} (-2,7,0) -- (2,7,0);
  \draw [my grey] (0,4,0) -- (0,7,0) (-2,7,0) -- (2,7,0);
  \coordinate (o) at (0,0,0);
  \path [draw=gray!70, text=gray, fill=gray!20, opacity=0.8, text opacity=1] (-1.5,4,1.75) coordinate (a) -- ++(0,0,-3.5) coordinate (b) -- ++(3,0,0) coordinate (c) -- ++(0,0,3.5) coordinate (d) -- cycle node [pos=.95, above, sloped, anchor=south west] {$z=f$} ;
%   \foreach \i in {a,b,c,d} \node [red, font=\scriptsize] at (\i) {\i};
  \draw [my grey] (-2,0,0) -- (2,0,0) (0,0,0) -- (0,4,0) (0,0,0) -- (0,0,2);
  \draw [thick, ->, every node/.style={font=\footnotesize, inner sep=0pt}] (o) node [anchor=north west] {$F_c$} (o) edge node [pos=1, anchor=north east] {$z_c$} ++(0,1,0) edge node [pos=1, anchor=north] {$y_c$} ++(0,0,1) -- ++(1,0,0) node [anchor=north west] {$x_c$};
  \draw [my box] (a) ++(0,0,-2.25) coordinate (p1) -- ++(2.25,0,0) coordinate (p2) -- ++(0,0,-1.25) coordinate (p3);
  \foreach \i in {0,1,...,8} \draw [my box] (p1) ++(\i*.25,0,0) -- ++(0,0,-.25);
  \foreach \i in {0,1,...,5} \draw [my box] (p2) ++(0,0,-\i*.25) -- ++(-.25,0,0);
  \draw [my box] (p1) ++(0,0,-.25) -- ++(2,0,0) -- ++(0,0,-1);
  \draw [my dashed, cyan] ($(b)!1/2!(c)$) -- ($(d)!1/2!(a)$) node [below=15pt, anchor=north] {$y$};
  \draw [my dashed, cyan] ($(b)!1/2!(a)$) -- ($(d)!1/2!(c)$) node [above right=17pt, anchor=north west] {$x$};
  \draw [my dashed, green!50!black, <->] (a) node [below=15pt, anchor=north] {$v$} -- (b) -- (c) node [above right=17pt, anchor=north west] {$u$};
  \path [green!50!black, every node/.style={font=\scriptsize, inner sep=0pt}] (p2) node [above right, anchor=south west] {$(u,v)$};
  \path (p2) ++(-.125,0,0) coordinate (q2) ++(0,0,-.125) coordinate (r2);
  \draw [my blue=1] ($($(a)!1/2!(b)$)+($(q2)-(p1)$)$) coordinate (s2) -- (r2) node (d1) {};
  \scoped[on background layer]{\draw [my blue=1.75] ($($1.75*($(s2)-(0,4,0)$)$)+(0,7,0)$) -- ++($1.75*($(r2)-(s2)$)$) node (d2) [label={[label distance=-20pt]above:{$P=(X,Y,Z)$}}] {};}
  \draw [my vectors] (0,4,.1) -- ($(s2)+(0,0,.1)$) node [below, my label, sloped] {$\vec{u}$};
  \draw [my vectors] (-.1,4,0) -- ($(q2)-(s2)+(-.1,4,0)$) node [left, my label] {$\vec{v}$};
  \draw [my red] (o) -- (d1.center);
  \scoped[on background layer]{\draw [my red] (d1.center) -- (d2.center);}
  \path [description] (0,4,0) [out=-95, in=95] to (-.75,4,.25) node {ponto\\principal} (0,6.5,0) [out=-95, in=95] to (-.75,6.5,.25) node {eixo\\\'otico};
\end{tikzpicture}
\end{document}

Answer

我决定使用重新绘制图片，而不是纠缠于现有代码tikz-3dplot。