切掉部分径向阴影作为节点形状的扇形

Question

经过反复尝试，我找到了一种在中实现阴影的方法path picture。不再如此calc，现在一切都是简单的样式

       shade radial={
        shade radial color={1}{black},
        shade radial color={2}{green},
        shade radial color={3}{blue},
        shade radial color={4}{red}
        },

您可以将其添加到节点。

（阴影被称为color four radial而不是four color radial承认cfr 的开创性工作。

梅威瑟：

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{shapes.geometric}
\tikzset{shade radial/.code={%
        \tikzset{%
          color four radial/.cd,% I know "four color radial" sounds better but cfr should be acknowledged here
          #1,
          cfradial
        }},
color four radial/.cd,  
shade radial color/.code n args={2}{\colorlet{cfradialcolor#1}{#2}},
shade radial color={1}{black},
shade radial color={2}{black},
shade radial color={3}{white},
shade radial color={4}{white},
cfradial/.style={/tikz/path picture={
\xdef\radius{\radius}
\pgfmathsetmacro{\rone}{0.6*\radius}
\pgfmathsetmacro{\rtwo}{0.8*\radius}
\pgfdeclareradialshading[cfradialcolor1,cfradialcolor2,cfradialcolor3,cfradialcolor4]{cfradial}%shading name see pgfmanual 3.01a, p. 1083
                            {\centerpoint}%center point 
                            {color(0pt)=(cfradialcolor1); %color specifications
                             color(\rone pt)=(cfradialcolor2);
                             color(\rtwo pt)=(cfradialcolor3);
                             color(\radius)=(cfradialcolor4) %
                            }
\typeout{\radius,\rone,\rtwo}
\pgfuseshading{cfradial}
}}}

\begin{document}  
\begin{tikzpicture}
\tikzset{shape circlesec/.style={
        draw,
        line width=0.1pt,
        inner xsep=0pt,
        inner ysep=0pt,
    } 
}
\node [shape=circular sector, 
       style=shape circlesec,
       inner sep=0cm,
       shade radial={
        shade radial color={1}{black},
        shade radial color={2}{green},
        shade radial color={3}{blue},
        shade radial color={4}{red}
        },
       circular sector angle=30,
       shape border uses incircle,
       shape border rotate=-165,
       anchor=sector center,inner sep=-2mm,%
       minimum size = 6.6cm,%has an effect if the original size was smaller
      ] 
   (maerz) at (0,0) {};
\end{tikzpicture} 
\end{document}

旧答案：我试图回答这个好问题。我认为这是一个非常按照您建议的方式使用，这是一个聪明的想法\pgfdeclareradialshading。我所做的只是清理一下，并编写了一个 pgfkeys 代码，该代码根据可以提取的某些输入声明阴影，例如通过calc。我还剔除了对问题可能不重要的元素，例如网格。

\documentclass[margin=100pt]{standalone}
\usepackage{tikz}     
\makeatletter
% from https://tex.stackexchange.com/a/127045/121799
\tikzset{use path/.code=\tikz@addmode{\pgfsyssoftpath@setcurrentpath#1}}
\makeatother
\usetikzlibrary{calc,shapes.geometric,backgrounds,fadings}
\tikzset{my radial shader/.code args={#1 with radius #2}{
\pgfmathsetmacro{\rone}{0.6*#2}
\pgfmathsetmacro{\rtwo}{0.8*#2}
\typeout{#1:\rone,#2}
\pgfdeclareradialshading{#1}%shading name
                            {\pgfpoint{0}{0}}%center point pgfman301a,p.1083
                            {rgb(0pt)=(1.00,0.00,0.00); %color specification
                             rgb(\rone pt)=(0.60,1.00,0.00);
                             rgb(\rtwo pt)=(0.30,1.60,1.00);
                             rgb(#2)=(0.00,0.30,1.50) %extent of the circle
                            }
}}

\begin{document}  
\begin{tikzpicture}
\tikzset{shape circlesec/.style={
        draw,
        line width=0.1pt,
        inner xsep=0pt,
        inner ysep=0pt,
    } 
}
\node [save path=\pathA,
       shape=circular sector, 
       style=shape circlesec,
       inner sep=0cm,
       circular sector angle=30,
       shape border uses incircle,
       shape border rotate=-165,
       anchor=sector center,inner sep=-2mm,%
       minimum size = 6.6cm,%has an effect if the original size was smaller
      ] 
   (maerz) at (0,0) {};

   \begin{scope}[on background layer]
   \path    let \p1=($(maerz.arc center)-(maerz.sector center)$),
             \n1={veclen(\y1,\x1)} in 
             [my radial shader={rad1 with radius \n1}];
   \clip[use path=\pathA];               
   \pgfuseshading{rad1};
   \end{scope}
\end{tikzpicture} 
\end{document}

我相信这可以通过path picture等来简化很多。但这至少是可行的。

Answer 1