How to make letters thickness on 3D picture constant

Question

The following picture is drawn in Asymptote. In the first screenshot the letters look normal (Acrobat Reader's interactive viewing mode is disabled). In the second screenshot the letters look thicker (Acrobat Reader's interactive viewing mode is enabled).

Question: how to make them the same thickness, both before and after clicking on the interactive picture.

Clarification: right after clicking on the interactive picture (to activate interactive viewing mode), letters look thicker.

The complete .tex file for generating the picture:

\documentclass{article}
\usepackage[inline]{asymptote}
\begin{document}
\begin{asy}
settings.render=20;
import solids;
currentprojection = perspective(0,100,25);
viewportmargin=(0.1cm,0.1cm);
unitsize(1cm);
triple pO=(0,0,0);
label("$A$",X,W);
label("$B$",0*X,W);
dot((0,0,0));
dot((0,0,1));

\end{asy}
\end{document}