2

I would like to represent the ɛ-neighborhood of a convex polygon, which is the Minkowski sum of the polygon and a disk of radius ɛ. The polygon is given by its vertices, from which of course I could calculate a drawing, but I hope that there is a simpler solution using TikZ (though I'm equally happy with any other solution). Here is an example, the ɛ-neighborhood of a triangle.

azetina
  • 28,884
domotorp
  • 389
  • 1
    What have you got so far? If you give us the code for the non-simple solution, probably somebody can help produce the simpler. Right now, this is a do-it-for-me-after-working-out-what-it-I-want-done. – cfr Jun 23 '16 at 02:28
  • @cfr: If I had the code of the non-simple solution, why would I bother to get a code for a simple solution? I don't want anyone to "do-it-for-me", I want someone to tell me how to do it. I'm sorry if the "what-I-want-done" part is not clear, I've tried to update it now. – domotorp Jun 23 '16 at 02:37
  • Look at this: http://tex.stackexchange.com/a/129854/10898 – azetina Jun 23 '16 at 06:03
  • @azetina: I don't want an svg, I've only linked to it so that people can see what kind of image I would like. – domotorp Jun 23 '16 at 06:30
  • 1
    This not so difficult. You need (1) select the program, in which you like to draw (pstrick, tikz,...), then (2) search here or in http://www.texample.net/ for similar drawings and (3) start to draw. When you stuck with it, ask here, how to solve your particular problem. Otherwise, see @cfr comment. – Zarko Jun 23 '16 at 06:36

1 Answers1

5

A starting point :

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc}

\def\radius{.5cm}

\begin{document}
\begin{tikzpicture}
\coordinate (a) at (0,0);
\coordinate (b) at (3,-1);
\coordinate (c) at (2,2);
\foreach \nd in {a, b, c} {\draw (\nd) circle (\radius);}
\draw ($(a)!\radius!-90:(b)$) -- ($(b)!\radius!90:(a)$) ($(b)!\radius!-90:(c)$) -- ($(c)!\radius!90:(b)$) ($(c)!\radius!-90:(a)$) -- ($(a)!\radius!90:(c)$) ($(a)!\radius!-90:(b)$);
\draw[dashed] (a) -- (b) -- (c) -- cycle;
\end{tikzpicture}

\end{document}

Christoph Frings
  • 1,527