Est-ce que cela répond à votre question ? % !TEX lualatex \documentclass{standalone} \usepackage{luamplib} \everymplib{beginfig(1);} \everyendmplib{endfig;} \begin{document} \begin{mplibcode} path P; P = (0,0){right} .. (2cm,4cm){up} .. (4cm,5cm){right} .. (5cm,6cm){up} .. (8cm,7cm){right}; draw P withpen pencircle scaled 2pt withcolor .7 white; s = 5mm; for t=0 step s until arclength P: drawdot point arctime t of P of P withpen pencircle scaled 4pt withcolor red; draw (point arctime t of P of P)--(point arctime t of P of P+direction arctime t of P of P); endfor \end{mplibcode} \end{document} % Local Variables: % TeX-engine: luatex % End:

Est-ce que cela répond à votre question ? \documentclass{standalone} \usepackage{luamplib} \everymplib{beginfig(1);} \everyendmplib{endfig;} \begin{document} \begin{mplibcode} path P; P = (0,0){right} .. (2cm,4cm){up} .. (4cm,5cm){right} .. (5cm,6cm){up} .. (8cm,7cm){right}; draw P withpen pencircle scaled 2pt withcolor .7 white; s = 5mm; for t=0 step s until arclength P: drawdot point arctime t of P of P withpen pencircle scaled 4pt withcolor red; draw (point arctime t of P of P)--(point arctime t of P of P+direction arctime t of P of P); endfor \end{mplibcode} \end{document} % Local Variables: % TeX-engine: luatex % End: