Ok, that was the theoretical part. The practical part consists of two macros built on rotatebox and scalebox.
Code: Select all
\usepackage{graphicx}
%\hshearbox{vertical_prescale_times_shearfactor}{one_divide_by_shearfactor}{content}
% an initial vertical downscale is often necessary for a 3d projection
\newcommand{\hshearbox}[3]{\scalebox{0.866025}[#2]{\rotatebox{210}%
{\scalebox{1.73205}[-0.57735]{\rotatebox{60}{\scalebox{-1.1547}[#1]{#3}}}}}}
%\vshearbox{horizontal_prescale_times_shearfactor}{one_divide_by_shearfactor}{content}
% an initial horizontal downscale is often necessary for a 3d projection
\newcommand{\vshearbox}[3]{\scalebox{#2}[0.866025]{\rotatebox{210}%
{\scalebox{-0.57735}[1.73205]{\rotatebox{60}{\scalebox{#1}[-1.1547]{#3}}}}}}
But maybe, there is a more direct way to do shear transforms.