随机 3D 形状

Question

我创建了一张随机电荷分布的图片，它现在看起来像这样

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{intersections, decorations,circuits.ee.IEC, calc, decorations.markings, patterns}

\usepackage{pgfplots}
\pgfplotsset{compat=newest}

\begin{document}

\begin{tikzpicture}

\definecolor{mygray}{gray}{0.8}

\draw [fill=mygray, decoration={random steps, segment length =.5cm, amplitude=.5cm}, decorate , rounded corners=.3cm] (-.5,0) -- (-.25, 3) -- (1,2) -- (1.2,-.5) -- (-.5,0);

\draw[->] (-.5,0) -- (4,0);
\draw[->] (0,-.5) -- (0,4);
\draw[->] (0,0) -- (45:4) node[right]{$\vec r$};

\end{tikzpicture}

\end{document}

我现在的问题是：我怎样才能得到一个随机的 3D 形状？谨致问候

编辑：添加了包以提供一个最小的示例，对此深表歉意。

Answer 1

这是可以创建“圆形”斑点的东西，你可以通过几个参数来影响它的外观。不知为何，它有时会产生尺寸太大错误，但这并没有破坏它。

代码

\documentclass[tikz,border=2mm]{standalone}
\usetikzlibrary{decorations.pathmorphing}

\begin{document}

\pgfmathtruncatemacro{\mynumsides}{20}
\pgfmathsetmacro{\myradius}{2}
\pgfmathsetmacro{\myradiusdeviation}{0.9}
\pgfmathsetmacro{\myangledeviation}{10}
\pgfmathsetmacro{\myrandomlength}{0.2}
\pgfmathsetmacro{\myrandomamplitude}{0.1}
\newcommand{\mycolor}{red!80!yellow}
\pgfmathsetmacro{\myopacity}{0.4}
\pgfmathsetmacro{\myroundedcorners}{0.1}

\begin{tikzpicture}
    \draw[->] (-.5,0) -- (4,0);
    \draw[->] (0,-.5) -- (0,4);
    \draw[->] (0,0) -- (45:4) node[right]{$\vec r$};
    \pgfmathtruncatemacro{\maxindex}{\mynumsides-1}
    \pgfmathsetmacro{\angle}{360/\mynumsides}
    \fill[decoration={random steps,segment length=\myrandomlength cm,amplitude=\myrandomamplitude cm},decorate,ball color=\mycolor,opacity=\myopacity,rounded corners=\myroundedcorners cm,shift={(\myradius,\myradius)}]   (rand*\myangledeviation:\myradius+rand*\myradiusdeviation)
    \foreach \x in {1,...,\maxindex}
    {   -- (\x*\angle+rand*\myangledeviation:\myradius+rand*\myradiusdeviation)
    }
    -- cycle;
\end{tikzpicture}

\end{document}

输出

交替输出

\pgfmathtruncatemacro{\mynumsides}{20}
\pgfmathsetmacro{\myradius}{2}
\pgfmathsetmacro{\myradiusdeviation}{0.1}
\pgfmathsetmacro{\myangledeviation}{2}
\pgfmathsetmacro{\myrandomlength}{0.1}
\pgfmathsetmacro{\myrandomamplitude}{0.05}
\newcommand{\mycolor}{blue}
\pgfmathsetmacro{\myopacity}{0.4}
\pgfmathsetmacro{\myroundedcorners}{0.02}