Estilo de línea personalizado con decoración personalizada.

Question

Quiero crear una versión con bridas de tuberías 3D que parezcanla foto en la publicación original. Mi intento de "fuerza bruta" es el siguiente:

\documentclass[tikz]{standalone}

\begin{document}

\begin{tikzpicture} 
\definecolor{LPtgrey}{rgb}{.7,.7,.7}
\def\pipesize{1cm}
\def\flangesize{1.75*\pipesize}
\def\ft{0.2} % for flange thickness
\def\fg{0.02} % for flange gap
\def\xx{0.5} % length of middle of bend to inside edge of flange, ie, same as bend radius
\pgfsetcornersarced{\pgfpoint{0.5cm}{0.5cm}}
%pipe
\draw[color=LPtgrey!80!black, line width=\pipesize*0.4] (2,0)--(2,6)--(5,6)--(7,4)--(9,4);%
\draw[color=LPtgrey, line width=\pipesize*0.38] (2,0)--(2,6)--(5,6)--(7,4)--(9,4);%
\draw[color=LPtgrey!85, line width=\pipesize*0.35] (2,0)--(2,6)--(5,6)--(7,4)--(9,4);%
\draw[color=LPtgrey!70, line width=\pipesize*0.32] (2,0)--(2,6)--(5,6)--(7,4)--(9,4);%
\draw[color=LPtgrey!55, line width=\pipesize*0.29] (2,0)--(2,6)--(5,6)--(7,4)--(9,4);%
\draw[color=LPtgrey!45, line width=\pipesize*0.25] (2,0)--(2,6)--(5,6)--(7,4)--(9,4);%
\draw[color=LPtgrey!35, line width=\pipesize*0.20] (2,0)--(2,6)--(5,6)--(7,4)--(9,4);%
%flange 1
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (2,0)--(2,0+\ft);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (2,0)--(2,0+\ft);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (2,0)--(2,0+\ft);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (2,0)--(2,0+\ft);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (2,0)--(2,0+\ft);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (2,0)--(2,0+\ft);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (2,0)--(2,0+\ft);%
%flange 2
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (2,6-\xx-\ft-\fg-\ft)--(2,6-\xx-\ft-\fg);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (2,6-\xx-\ft-\fg-\ft)--(2,6-\xx-\ft-\fg);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (2,6-\xx-\ft-\fg-\ft)--(2,6-\xx-\ft-\fg);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (2,6-\xx-\ft-\fg-\ft)--(2,6-\xx-\ft-\fg);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (2,6-\xx-\ft-\fg-\ft)--(2,6-\xx-\ft-\fg);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (2,6-\xx-\ft-\fg-\ft)--(2,6-\xx-\ft-\fg);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (2,6-\xx-\ft-\fg-\ft)--(2,6-\xx-\ft-\fg);%
%flange 3
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (2,6-\xx-\ft)--(2,6-\xx);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (2,6-\xx-\ft)--(2,6-\xx);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (2,6-\xx-\ft)--(2,6-\xx);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (2,6-\xx-\ft)--(2,6-\xx);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (2,6-\xx-\ft)--(2,6-\xx);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (2,6-\xx-\ft)--(2,6-\xx);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (2,6-\xx-\ft)--(2,6-\xx);%
%flange 4
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (2+\xx,6)--(2+\xx+\ft,6);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (2+\xx,6)--(2+\xx+\ft,6);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (2+\xx,6)--(2+\xx+\ft,6);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (2+\xx,6)--(2+\xx+\ft,6);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (2+\xx,6)--(2+\xx+\ft,6);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (2+\xx,6)--(2+\xx+\ft,6);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (2+\xx,6)--(2+\xx+\ft,6);%
%flange 5
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (2+\xx+\ft+\fg,6)--(2+\xx+\ft+\fg+\ft,6);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (2+\xx+\ft+\fg,6)--(2+\xx+\ft+\fg+\ft,6);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (2+\xx+\ft+\fg,6)--(2+\xx+\ft+\fg+\ft,6);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (2+\xx+\ft+\fg,6)--(2+\xx+\ft+\fg+\ft,6);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (2+\xx+\ft+\fg,6)--(2+\xx+\ft+\fg+\ft,6);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (2+\xx+\ft+\fg,6)--(2+\xx+\ft+\fg+\ft,6);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (2+\xx+\ft+\fg,6)--(2+\xx+\ft+\fg+\ft,6);%
%flange 6
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (5-\xx-\ft-\fg-\ft,6)--(5-\xx-\ft-\fg,6);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (5-\xx-\ft-\fg-\ft,6)--(5-\xx-\ft-\fg,6);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (5-\xx-\ft-\fg-\ft,6)--(5-\xx-\ft-\fg,6);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (5-\xx-\ft-\fg-\ft,6)--(5-\xx-\ft-\fg,6);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (5-\xx-\ft-\fg-\ft,6)--(5-\xx-\ft-\fg,6);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (5-\xx-\ft-\fg-\ft,6)--(5-\xx-\ft-\fg,6);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (5-\xx-\ft-\fg-\ft,6)--(5-\xx-\ft-\fg,6);%
%flange 7
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (5-\xx-\ft,6)--(5-\xx,6);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (5-\xx-\ft,6)--(5-\xx,6);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (5-\xx-\ft,6)--(5-\xx,6);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (5-\xx-\ft,6)--(5-\xx,6);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (5-\xx-\ft,6)--(5-\xx,6);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (5-\xx-\ft,6)--(5-\xx,6);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (5-\xx-\ft,6)--(5-\xx,6);%
%flange 8
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (5+\xx,6-\xx)--(5+\xx+\ft,6-\xx-\ft);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (5+\xx,6-\xx)--(5+\xx+\ft,6-\xx-\ft);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (5+\xx,6-\xx)--(5+\xx+\ft,6-\xx-\ft);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (5+\xx,6-\xx)--(5+\xx+\ft,6-\xx-\ft);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (5+\xx,6-\xx)--(5+\xx+\ft,6-\xx-\ft);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (5+\xx,6-\xx)--(5+\xx+\ft,6-\xx-\ft);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (5+\xx,6-\xx)--(5+\xx+\ft,6-\xx-\ft);%
%flange 9
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (5+\xx+\ft+\fg,6-\xx-\ft-\fg)--(5+\xx+\ft+\fg+\ft,6-\xx-\ft-\fg-\ft);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (5+\xx+\ft+\fg,6-\xx-\ft-\fg)--(5+\xx+\ft+\fg+\ft,6-\xx-\ft-\fg-\ft);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (5+\xx+\ft+\fg,6-\xx-\ft-\fg)--(5+\xx+\ft+\fg+\ft,6-\xx-\ft-\fg-\ft);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (5+\xx+\ft+\fg,6-\xx-\ft-\fg)--(5+\xx+\ft+\fg+\ft,6-\xx-\ft-\fg-\ft);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (5+\xx+\ft+\fg,6-\xx-\ft-\fg)--(5+\xx+\ft+\fg+\ft,6-\xx-\ft-\fg-\ft);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (5+\xx+\ft+\fg,6-\xx-\ft-\fg)--(5+\xx+\ft+\fg+\ft,6-\xx-\ft-\fg-\ft);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (5+\xx+\ft+\fg,6-\xx-\ft-\fg)--(5+\xx+\ft+\fg+\ft,6-\xx-\ft-\fg-\ft);%
%flange 10
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (7-\xx-\ft-\fg-\ft,4+\xx+\ft+\fg+\ft)--(7-\xx-\ft-\fg,4+\xx+\ft+\fg);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (7-\xx-\ft-\fg-\ft,4+\xx+\ft+\fg+\ft)--(7-\xx-\ft-\fg,4+\xx+\ft+\fg);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (7-\xx-\ft-\fg-\ft,4+\xx+\ft+\fg+\ft)--(7-\xx-\ft-\fg,4+\xx+\ft+\fg);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (7-\xx-\ft-\fg-\ft,4+\xx+\ft+\fg+\ft)--(7-\xx-\ft-\fg,4+\xx+\ft+\fg);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (7-\xx-\ft-\fg-\ft,4+\xx+\ft+\fg+\ft)--(7-\xx-\ft-\fg,4+\xx+\ft+\fg);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (7-\xx-\ft-\fg-\ft,4+\xx+\ft+\fg+\ft)--(7-\xx-\ft-\fg,4+\xx+\ft+\fg);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (7-\xx-\ft-\fg-\ft,4+\xx+\ft+\fg+\ft)--(7-\xx-\ft-\fg,4+\xx+\ft+\fg);%
%flange 11
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (7-\xx-\ft,4+\xx+\ft)--(7-\xx,4+\xx);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (7-\xx-\ft,4+\xx+\ft)--(7-\xx,4+\xx);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (7-\xx-\ft,4+\xx+\ft)--(7-\xx,4+\xx);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (7-\xx-\ft,4+\xx+\ft)--(7-\xx,4+\xx);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (7-\xx-\ft,4+\xx+\ft)--(7-\xx,4+\xx);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (7-\xx-\ft,4+\xx+\ft)--(7-\xx,4+\xx);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (7-\xx-\ft,4+\xx+\ft)--(7-\xx,4+\xx);%
%flange 12
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (7+\xx,4)--(7+\xx+\ft,4);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (7+\xx,4)--(7+\xx+\ft,4);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (7+\xx,4)--(7+\xx+\ft,4);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (7+\xx,4)--(7+\xx+\ft,4);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (7+\xx,4)--(7+\xx+\ft,4);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (7+\xx,4)--(7+\xx+\ft,4);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (7+\xx,4)--(7+\xx+\ft,4);%
%flange 13
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (7+\xx+\ft+\fg,4)--(7+\xx+\ft+\fg+\ft,4);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (7+\xx+\ft+\fg,4)--(7+\xx+\ft+\fg+\ft,4);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (7+\xx+\ft+\fg,4)--(7+\xx+\ft+\fg+\ft,4);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (7+\xx+\ft+\fg,4)--(7+\xx+\ft+\fg+\ft,4);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (7+\xx+\ft+\fg,4)--(7+\xx+\ft+\fg+\ft,4);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (7+\xx+\ft+\fg,4)--(7+\xx+\ft+\fg+\ft,4);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (7+\xx+\ft+\fg,4)--(7+\xx+\ft+\fg+\ft,4);%
%flange 14
\draw[color=LPtgrey!80!black, line width=\flangesize*0.4] (9-\ft,4)--(9,4);%
\draw[color=LPtgrey, line width=\flangesize*0.38] (9-\ft,4)--(9,4);%
\draw[color=LPtgrey!85, line width=\flangesize*0.35] (9-\ft,4)--(9,4);%
\draw[color=LPtgrey!70, line width=\flangesize*0.32] (9-\ft,4)--(9,4);%
\draw[color=LPtgrey!55, line width=\flangesize*0.29] (9-\ft,4)--(9,4);%
\draw[color=LPtgrey!45, line width=\flangesize*0.25] (9-\ft,4)--(9,4);%
\draw[color=LPtgrey!35, line width=\flangesize*0.20] (9-\ft,4)--(9,4);%
\end{tikzpicture}
\end{document}

el resultado está bien:

La fuerza bruta funciona bien para giros de 90 grados, pero los ángulos de 45 grados tienen pestañas demasiado gruesas. Otros ángulos requieren demasiada trigonometría para calcular las posiciones de las bridas.

1. Debe haber una manera de definir un "estilo de línea" que es la combinación de 5 líneas superpuestas (no sé cómo).

2. Debe haber una manera de definir una decoración personalizada que termine cada línea (o cada nodo de una polilínea) para obtener el resultado deseado. ¿Giraría la decoración para formar el mismo ángulo que la línea?

Idealmente, me gustaría usar código como:

\draw[pipe,style=flange,diameter=3cm](2,0)--(2,6)--(5,6);

y se encargarían de todos los cálculos asociados con la ubicación de las bridas. Dibujaré MUCHOS diagramas de tuberías en un futuro próximo y agradecería cualquier código útil que lo haga más fácil.

Answer 1

Aquí se demuestran dos enfoques. Ambos usan repetidamente la preactiontecla con diferentes anchos de línea y colores para dibujar la tubería (y también la brida). El primer enfoque utiliza la markingsdecoración para postactioncolocar las pestañas. El segundo utiliza la show path constructiondecoración para colocar pestañas al principio y al final de linetolos curvetosegmentos.

\documentclass[tikz,border=5]{standalone}
\usetikzlibrary{decorations.markings,decorations.pathreplacing,calc}
\makeatletter
\tikzset{every pipe/.code={%
  \pgfmathloop
  \ifnum\pgfmathcounter>20
  \else
    \pgfmathsetmacro\i{\pgfmathcounter}%
    \pgfmathsetmacro\j{80-\pgfmathcounter*3}%
    \tikzset{preaction/.expanded={line width=(\pipewidth)*(1-\i*\i/500),
        draw=black!50!white!\j!white}}%
  \repeatpgfmathloop
},
every flange/.style 2 args={insert path={
  let \p1=(#1), \p2=(#2),\n1={atan2(\y2-\y1, \x2-\x1)} in
    [shift={(\p1)}, rotate=\n1, pipe width={(\pipewidth)*4/3}, every pipe] 
      (0.01,0) -- (0.2,0)
}},
flanges/.style={postaction={%
  /utils/exec={
    \@for\pos:=#1\do{%
      \tikzset{decoration/.expanded={markings,
        mark=at position \pos\space with {
          \noexpand\path [pipe width=\pipewidth*4/3, every pipe] (0.01,0) -- (0.2,0);
    }}}}}, 
  decorate}},
pipe width/.code=\pgfmathsetlengthmacro\pipewidth{#1},
pipes/.style={
  every pipe,
  postaction={decoration={show path construction,
    lineto code={
      \path [every flange={\tikzinputsegmentfirst}{\tikzinputsegmentlast}];
      \path [every flange={\tikzinputsegmentlast}{\tikzinputsegmentfirst}];
    },
    curveto code={
      \path [every flange={\tikzinputsegmentfirst}{\tikzinputsegmentsupporta}];
      \path [every flange={\tikzinputsegmentlast}{\tikzinputsegmentsupportb}];
    }
}, decorate}},
pipe/.style={
  every pipe,
  flanges={0, 1}
}}
\begin{document}
\begin{tikzpicture}[line join=round, pipe width=0.5cm]
\path [pipes] (0,4) -- (0,1) arc (180:330:1) (-1,3) -- (1,3);
\path [pipes] (3,-1/3) -- (3,2);
\path [pipes] (4,-1/3) -- (4,4);
\path [pipe]  (11/2,3) -- (4,5/4) -- (11/2,0);
\path [pipe]  (13/2,5/2) -- (8,5/2) -- (13/2,0) -- (8,0);
\path [pipes] (4,2) ellipse [x radius=6, y radius=4];
\end{tikzpicture}
\end{document}