pgf 的问题：缺少数字，视为零（如何正确设置域？）

Question

我有这个代码

\documentclass[border=3pt]{standalone}

%Drawing
\usepackage{tikz}
\usepackage{pgfplots}
%3D
\usepackage{tikz-3dplot}

%Tikz Library
\usetikzlibrary{angles, quotes, intersections}

%Styles
\tikzset{axis/.style={thick,-latex}}
\tikzset{vec/.style={thick,blue}}
\tikzset{univec/.style={thick,red,-latex}}

%Notation
\usepackage{physics}
\usepackage{bm}

\begin{document}
    
    %Layers
    \pgfdeclarelayer{background}
    \pgfdeclarelayer{foreground}
    
    \pgfsetlayers{background, main, foreground}
    
    \tdplotsetmaincoords{70}{110}
    %
    \pgfmathsetmacro{\thetavec}{48.17}
    \pgfmathsetmacro{\phivec}{63.5}
    %
    
    \begin{tikzpicture}[tdplot_main_coords]
        %Areas
        \begin{pgfonlayer}{main}
            \path[opacity=0.5, fill=black!20] (0,0,0) -- ++(11.5,0,0) -- ++(0,9,0) -- +(-11.5,0,0) -- cycle;
            \path[opacity=0.5, fill=blue!20] (0,0,0) -- (2,4,0) -- (10.1,0,0) -- cycle;
            \path[opacity=0.5, fill=red!20] (0,0,0) -- (2,4,4) -- (3.6,7.2,0) -- cycle;     
        \end{pgfonlayer}
        
        %Axis
        \begin{pgfonlayer}{background}
            \draw[axis] (0,0,0) -- (0,9.5,0) node [pos=1.05] {$y$};
            \draw[axis] (0,0,0) -- (0,0,5.5)  node [pos=1.05] {$z$};  
        \end{pgfonlayer}
        \begin{pgfonlayer}{main} 
            \draw[axis] (0,0,0) -- (12,0,0) node [pos=1.05] {$x$};  
        \end{pgfonlayer}
        
        %Secondary
        \begin{pgfonlayer}{background}
            \tdplotsetcoord{R}{6.5}{90+\thetavec}{\phivec}
            \draw[axis] (2,4,4) -- ($(R) + (2,4,4)$) node [pos=1.025] {$\theta$};   
        \end{pgfonlayer}
        
        \begin{pgfonlayer}{foreground}
            \tdplotsetcoord{R'}{5.37}{90+\thetavec}{\phivec}
            \draw[thick] (2,4,4) -- ($(R') + (2,4,4)$); 
            \tdplotsetcoord{S}{5.5}{90}{\phivec}
            \draw[axis] (2,4,0) -- ($(S)+(2,4,0)$) node [pos=1.1] {$\varpi$};
        \end{pgfonlayer}
        
        %Unit Vectors
        \begin{pgfonlayer}{foreground}
            \tdplotsetcoord{p}{1}{90}{\phivec}
            \draw[univec] (2,4,0) -- ($(p)+(2,4,0)$) node [pos=0.3,below] {$\vu*{\varpi}$};
            \tdplotsetcoord{P'}{7}{\thetavec}{\phivec}
            \draw[univec] (0,0,0) -- (P') node [pos=1.05] {$\vu{r}$};
            \tdplotsetcoord{P'''}{1}{90+\thetavec}{\phivec}
            \draw[univec] (2,4,4) -- ($(P''') + (2,4,4)$) node [above right] {$\vu*{\theta}$};
            \draw[univec] (0,0,0) -- (1.3,0,0) node [pos=0.3, above left] {$\vu{x}$};
            \draw[univec] (0,0,0) -- (0,0,1) node [left] {$\vu{z}$};
        \end{pgfonlayer}
        \begin{pgfonlayer}{background}
            \tdplotsetcoord{P''}{1}{90}{90+\phivec}
            \draw[univec] (2,4,0) -- ($(P'') + (2,4,0)$) node [pos=1.3] {$\vu*{\phi}$};
            \draw[univec] (0,0,0) -- (0,1,0) node [above] {$\vu{y}$};
        \end{pgfonlayer}
        %%
        \tdplotsetcoord{K}{10}{90}{90+\phivec}
        \draw[thick] (2,4,0) -- ($(2,4,0) - (K)$);
        
        
        
        %Vectors
        \begin{pgfonlayer}{foreground}
            \tdplotsetcoord{P}{6}{\thetavec}{\phivec}
            \draw[vec] (0,0,0) -- (P) node [midway, above] {$r$};
            \draw[thick] (0,0,0) -- (2,4,0) node [pos=0.6, above] {$\varpi$};
        \end{pgfonlayer}
        
        %Help Lines
        \begin{pgfonlayer}{background}
            \draw[dashed] (0,4,0) -- (2,4,0) node [pos=-0.3] {$y$};
            \draw[dashed] (0,0,4) -- (2,4,4) node [pos=-0.1] {$z$};
            \draw[dashed, tdplot_main_coords] (4.47,0,0) arc (0:90:4.47);
        \end{pgfonlayer}
        \begin{pgfonlayer}{main}
            \draw[dashed] (2,4,4) -- (2,4,0);
            \draw[dashed] (2,0,0) -- (2,4,0) node [pos=-0.1] {$x$};
            \draw[dashed, tdplot_main_coords] (4.47,0,0) arc (0:\phivec:4.47);
        \end{pgfonlayer}
        
        
        %Point
        \begin{pgfonlayer}{foreground}
            \node[fill=black, circle, inner sep=0.8pt] at (2,4,4) {};
        \end{pgfonlayer}
        
        %Angles
        \begin{pgfonlayer}{main}
            \tdplotdrawarc{(0,0,0)}{0.7}{0}{\phivec}{below}{$\phi$}
            %
            \tdplotsetthetaplanecoords{\phivec}
            \tdplotdrawarc[tdplot_rotated_coords]{(0,0,0)}{0.5}{0}{\thetavec}{}{}
            \node at (0,0.25,0.67) {$\theta$};
        \end{pgfonlayer}
        \begin{pgfonlayer}{background}
            \tdplotsetthetaplanecoords{\phivec}
            \tdplotdrawarc[tdplot_rotated_coords]{(0,8.05,0)}{0.4}{140}{90}{}{}
            \node at (4.5,8,0) {$\theta$};
        \end{pgfonlayer}
        
        
    \end{tikzpicture}
    
\end{document}

我收到错误： 缺失数字，视为零。...是]（0,0,0）--（0,9.5,0）节点[pos=1.05] {

但是读完以下内容后，我不知道如何正确设置域：

pgf 图：缺失数字，视为零