They are or not parallels?

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Forfatter

OSjerick

Sidst opdateret

10 år siden

Licens

Creative Commons CC BY 4.0

Resumé

The perpendicular lines that do not match row to row create an illusion of the lines between them being not parallel.

Submitted as an answer to the Showcase of Optical Illusions question on TeX SX.

Click the Illusions tag below to see more!

Tags

TikZ Optical Illusions

Find flere Eksempler

% Source: http://tex.stackexchange.com/a/149780/23931
\documentclass[tikz]{standalone}
\usetikzlibrary{calc}
\begin{document}
    \pagecolor{gray}
    \begin{tikzpicture}
        \pgfmathsetmacro{\offsety}{.05};
        \foreach \y / \offsetx in {0/0.3,1/0.5,2/0.3,3/0,4/0.3,5/0.5,6/0.3,7/0,8/0.3}
            \foreach \x in {0,...,10}{%
                \pgfmathifthenelse{mod(\x,2) == 0}{"black"}{"white"}
                %\ifodd\x \def\squarecolor{white} \else \def\squarecolor{black} \fi %Other way, use \squarecolor inside fill options
                \fill[\pgfmathresult] ($(\x,\y)+(\offsetx,\offsety*\y)$) rectangle +(1,1);
            }
    \end{tikzpicture}
\end{document}