# TikZ: showing a plane moving in 3 space

I have 2 identical planes a distance of \Delta t apart. I want to show that first plane is being pushed in the direction of the second plane.

I was thinking maybe some randomly placed arrows tangent to the planes pointing from plane one to plane two.

1. Would this be the way to go?
2. How can I set up a \foreach command and specify 5 random arrows starting in the area of the plane? That is, not passing through the first plane just touching it and moving away tangent to the plane.

Or is there a better way to show this?

\documentclass[convert = false, tikz]{standalone}

\usepackage[utf8]{inputenc}
\renewcommand{\rmdefault}{ppl}
\usepackage[scaled]{helvet}
\usepackage{courier}
\usepackage{eulervm}
\normalfont
\usepackage[T1]{fontenc}
\usepackage{textcomp}

\usepackage{amsmath}
\usepackage{tikz-3dplot}

\begin{document}
\tdplotsetmaincoords{60}{130}
\begin{tikzpicture}[tdplot_main_coords]
\coordinate (O) at (0, 0, 0);

\draw[-latex] (O) -- (5, 0, 0) node[font = \small, pos = 1.1] {$$x$$};
\draw[-latex] (O) -- (0, 5, 0) node[font = \small, pos = 1.1] {$$y$$};
\draw[-latex] (O) -- (0, 0, 4) node[font = \small, pos = 1.1] {$$z$$};
\draw[dashed] (O) -- (-3, 0, 0);

\filldraw[blue, opacity = .6] (4, 0, 0) -- (4, 5, 0) -- (4, 5, 4) --
(4, 0, 4) -- cycle;
\filldraw[blue, opacity = .6] (-2, 0, 0) -- (-2, 5, 0) -- (-2, 5, 4) --
(-2, 0, 4) -- cycle;

\draw[latex-latex] (4, 5, 2) -- (-2, 5, 2) node[font = \small, fill = white,
inner sep = 0, pos = .5] {$$\Delta t$$};
\draw[|-|] (4, 2.5, 4) -- (-2, 2.5, 4) node[font = \small, fill = white,
inner sep = 0, pos = .5] {$$v\Delta t$$};
\end{tikzpicture}
\end{document}


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@downvoter care to elaborate? –  dustin Aug 16 '13 at 0:45

I think placing random arrows pointing from one plane to the other is not very parcimonious and may be confusing. Why not just draw the velocity vector (to indicate the translation) and some dashed lines (to indicate that the two planes remain parallel)?

\documentclass[convert = false, tikz]{standalone}

\usepackage[utf8]{inputenc}
\renewcommand{\rmdefault}{ppl}
\usepackage[scaled]{helvet}
\usepackage{courier}
\usepackage{eulervm}
\normalfont
\usepackage[T1]{fontenc}
\usepackage{textcomp}

\usepackage{amsmath}
\usepackage{tikz-3dplot}

\begin{document}
\tdplotsetmaincoords{60}{130}
\begin{tikzpicture}[tdplot_main_coords]
\coordinate (O) at (0, 0, 0);

\draw[-latex] (O) -- (5, 0, 0) node[font = \small, pos = 1.1] {$$x$$};
\draw[-latex] (O) -- (0, 6, 0) node[font = \small, pos = 1.1] {$$y$$};
\draw[-latex] (O) -- (0, 0, 5) node[font = \small, pos = 1.1] {$$z$$};

\filldraw[blue, opacity = .4]
(-2, 0, 0)
-- (-2, 5, 0)
-- (-2, 5, 4)
-- (-2, 0, 4)
-- cycle;

\draw[dashed,thin] (4,0,0) -- (-2,0,0);
\draw[dashed,thin] (4,5,0) -- (-2,5,0);
\draw[dashed,thin] (4,5,4) -- (-2,5,4);
\draw[dashed,thin] (4,0,4) -- (-2,0,4);

\draw[latex-,thick]
(1, 5, 4)
-- (-2, 5, 4) node[
font = \small,
fill = white,
inner sep = 2pt,
pos = .5,
] {$$v$$};
\draw[|-|]
(4, -.7, 4)
-- (-2, -.7, 4) node[
opacity=1,
font = \small,
fill = white,
inner sep = 2pt,
pos = .5,
] {$$v\Delta t$$};

\draw[dashed,thin,gray] (4,-.7,4) -- (4,0,4);
\draw[dashed,thin,gray] (-2,-.7,4) -- (-2,0,4);

\filldraw[blue, opacity = .6]
(4, 0, 0)
-- (4, 5, 0)
-- (4, 5, 4)
-- (4, 0, 4)
-- cycle;
\end{tikzpicture}
\end{document}

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