\documentclass{standalone}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{fourier}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}

\begin{document}

\begin{tikzpicture}
\begin{axis}[
  colormap={mygray}{color=(gray!10) color=(gray)},
  mesh input=patches,
  patch type=triangle,
  view={5}{50}
]
\addplot3[surf] table {
  x  y  z
  0  0  1
  2  0  2
  1  2  2

  2  0  2
  1  2  2
  3  2  2

  2  0  2
  3  2  2
  4  0  1.8

  4  0  1.8
  3  2  2
  5  2  3

  4  0  1.8
  5  2  3
  6  0  1.7

  1  2  2
  3  2  2
  2  4  2.5

  3  2  2
  2  4  2.5
  4  4  2.6

  3  2  2
  4  4  2.6
  5  2  3

  2  4  2.5
  4  4  2.6
  3  6  2.7
};
\end{axis}
\end{tikzpicture}

\end{document}