%% Workaround for using tikz version in texlive 2019.
%% See https://github.com/pgf-tikz/pgf/issues/675
%\unprotect
%\def\XC@tgt@mod#1{#1}
%\def\XC@sdef#1#2{\edef#1{#2}}
%\protect

\setupcolors[state=start]
\usemodule[pgfplots]
\starttext
\starttikzpicture
  \startaxis
    \addplot3 [
      surf,
      shader=interp,  % works with shader=flat
      samples=10,
      domain=0:1,
      ] {x^2*y};
  \stopaxis
\stoptikzpicture
\stoptext

%%% local variables:
%%% mode: context
%%% TeX-master: t
%%% end:
