Use sans serif font for node numbers in cell_types.tex
% cnode(tag,x,y,z,label,label_pos)
\def\cnode(#1,#2,#3,#4,#5,#6){
-\node (#1) at (#2,#3,#4) [vertex,label=#6:$#5$] {};
+\node (#1) at (#2,#3,#4) [vertex,label=#6:$\mathsf{#5}$] {};
}
\pagestyle{empty}
