Create Half Cylinder Water Tank with Blue Fill Color

Question

I want to create this:

This is my MWE and what I have been trying manually:

\documentclass[tikz]{standalone}
\begin{document}
    \begin{tikzpicture}
    \draw (3,0) arc (360:180:1.5 and 1.5);% bottom half circle

    \draw (0,0) -- (3,3);% upper left line
    \draw (3,0) -- (6,3);% upper right line
    \draw (0,0) -- (3,0);% upper front line
    \draw (3,3) -- (6,3);% upper back line

    \draw (-1.25,1.5) node {$\phi$};

    \draw [fill=blue, fill opacity=.15] (0.2,-0.3) -- (3.2,2.7) -- (6.1,2.7) -- (3.1,-0.3) -- cycle;
    \draw [fill=blue, fill opacity=.35] (0.2,-0.6) -- (2.8,-0.6) -- (2.73,-0.8) -- (0.26,-0.8) -- cycle;
    \draw [fill=blue, fill opacity=.35] (2.8,-0.6) -- (2.73,-0.8) -- (6.2,2.6) -- (6.1,2.7) -- cycle;

    \draw [fill=blue, fill opacity=.15] (2.88,-0.3) arc (360:180:1.36 and 1.2);

\end{tikzpicture}

\end{document}

https://tex.stackexchange.com/questions/401630/how-can-i-fill-below-of-intersection-of-a-plane-and-a-cylinder-of-this-picture — minhthien_2016, Jan 20 '23 at 08:15
Yes I am on my way to make better 3D result. I will post the answer later if I finish good — Freya the Goddess, Jan 21 '23 at 05:50
Hi @Freya the Goddess ! Is my answer of any help for you? Does it fit into your project? — Daniel N, Jan 25 '23 at 06:31
Hi @DanielN , yes your work is really amazing, I am still a beginner in LaTeX thus need a lot of help from this forum.. — Freya the Goddess, Jan 25 '23 at 07:17
Looking better at your first try, I understand that you would like to have a darker layer drawn under the water's surface. In case you use my proposal, can you modify it and obtain that layer? — Daniel N, Jan 25 '23 at 08:21

score 4 · Accepted Answer · answered Jan 22 '23 at 11:31

The drawing uses the package tikz-3dplot; it gives the very useful option canvas is xy plane at z=....

Remarks

I redefined the coordinate system (a question of taste). The point of view can be changed by modifying the longitude and/or latitude (see the image below). The drawing is consistent if the observer stays in the first quadrant, i.e. if her latitude and longitude are contained in the interval (0, 90).
The elements composing the water tank are added from the background (negative z values) towards the foreground (z=0).
I couldn't figure out from the question's drawing if the front strip should continue as a layer through the water. If necessary, the layer can be constructed using the same techniques.
I didn't draw the sectional image on the right; I imagine it is a straightforward plane drawing. By the way, the 3d coordinates I'm using, "identify the Oxy plane with the screen. So the plane section is obtained by taking the elements having z=0.

The code

\documentclass[11pt, margin=23pt]{standalone}
\usepackage{tikz}
\usepackage{tikz-3dplot}
\usetikzlibrary{math, calc}
\begin{document}
\tikzset{%
  view/.style 2 args={% longitude / latitude
    z={({-sin(#1)}, {-cos(#1)sin(#2)})},
    x={({cos(#1)}, {-sin(#1)sin(#2)})},
    y={(0, {cos(#2)})},
    evaluate={%
      \tox={sin(#1)cos(#2)};
      \toy={sin(#2)};
      \toz={cos(#1)cos(#2)};
    }
  },
  w/.style={% water
    draw=cyan!40, fill=cyan!30, opacity=1, fill opacity=.9
  },
  w light/.style={% water, top face
    draw=cyan!35, fill=cyan!20, opacity=1, fill opacity=.95
  },
  tank/.style={% tank
    draw=blue!60!black, very thick, opacity=.95, line join=round
  },
  l/.style={draw=blue!50!gray, fill=blue!50!gray!40}
}
\tikzmath{
  real \r, \t, \aRG, \rw, \aw, \dl, \rl1, \rl2, \al1, \al2;
  \r = 2; % radius
  \t = 5\r; % tank's length
  \rw = .3\r; % controls the water's level
  \aw = {asin(\rw/\r)};
  \dl = 0.6\r; % for the lebels
  \rl1 = .4\r; % controls the layer's top level
  \rl2 = .55*\r; % controls the layer's bottom level
  \al1 = {asin(\rl1/\r)};
  \al2 = {asin(\rl2/\r)};
}
\begin{tikzpicture}[view={30}{11}, % latitude longitude
  every node/.style={scale=.8, text=black, text opacity=1},
  evaluate={\aRG = {atan2(-\tox, \toy)};}] % critical ruling's angle
% tank / back side
  \path[tank, canvas is xy plane at z=-\t] (180: \r) arc (180: 360: \r);
  \path[tank] ({\rcos(\aRG)}, {\rsin(\aRG)}, 0)
  -- ({\rcos(\aRG)}, {\rsin(\aRG)}, -\t);
% water
  \path[w, canvas is xy plane at z=0]
  ({180 +\aw}: \r) arc ({180 +\aw}: {360 -\aw}: \r) -- cycle;
  \path[w light, canvas is zx plane at y={-\rw}]
  (0, -{\rcos(\aw)}) -- (0, {\rcos(\aw)})
  -- (-\t, {\rcos(\aw)}) -- (-\t, -{\rcos(\aw)}) -- cycle;
  \path[w] ({\rcos(-\aw)}, {\rsin(-\aw)}, 0)
  {%
    [canvas is xy plane at z=0]
    -- ({-\aw}: \r) arc ({-\aw}: {\aRG}: \r)
  }{%
    [canvas is xy plane at z=-\t]
    -- ({\aRG}: \r) arc ({\aRG}: {-\aw}: \r)
  } -- cycle;
% layer
  \path[l, canvas is xy plane at z=0]
  ({180 +\al1}: \r) arc ({180 +\al1}: {180 +\al2}: \r)
  -- ({-\al2}: \r) arc ({-\al2}: {-\al1}: \r) -- cycle;
% tank / top and front side
  \path[tank, canvas is zx plane at y=0]
  (0, -\r) -- (0, \r) -- (-\t, \r) -- (-\t, -\r) -- cycle;
  \path[tank, canvas is xy plane at z=0] (180: \r) arc (180: 360: \r);
\draw[gray, line width=.5pt, canvas is xy plane at z=0]
  (0, -\r) -- ++(-\dl -\r, 0) node (T0) {}
  ({180 +\aw}: \r) -- ++(-.5*\dl, 0) node (W1) {}
  ++(0, -\r +\rw) node (W0) {}
  (-\r, 0) -- ++(-\dl, 0) node (T1) {};
  \draw[gray, line width=.5pt, canvas is xy plane at z=-\t]
  (-\r, 0) -- ++(-\dl, 0) node (T2) {};
  \path[canvas is zx plane at y=0]
  (T1) edge[gray, <->, line width=.5pt] node[pos=.5, fill=white] {$50$} (T2)
  edge[gray, <->, line width=.5pt] node[pos=.5, fill=white] {$10$} (T0)
  (W1) edge[gray, <->, line width=.5pt] node[pos=.5, fill=white] {$?$} (W0);
\end{tikzpicture}
\end{document}

Spectacular....great answer. +1 – Sebastiano Jan 22 '23 at 11:41 — Sebastiano, Jan 22 '23 at 11:41
Magnifique, tres bien!!! – Freya the Goddess Jan 25 '23 at 07:17 — Freya the Goddess, Jan 25 '23 at 07:17

Create Half Cylinder Water Tank with Blue Fill Color

1 Answers1