Include webgl picture from html file into latex

You can have both, interactive 3D content that opens on click and a nicely rendered vector image for printing and PDF viewers that don't support PRC. For this, add

import three;
settings.render = 0;

at top of the asy code.

Compile example.tex with

pdflatex example
asy example-1.asy
pdflatex example

Input example.tex:

documentclass[varwidth,border=3pt]{standalone}

usepackage{hyperref,calc}
usepackage[inline]{asymptote}

setlength{textwidth}{widthof{begin{NoHyper}url{https://asymptote.sourceforge.io/gallery/3Dwebgl}end{NoHyper}}}

begin{document}

Example verb+cylinder.asy+, taken from
url{https://asymptote.sourceforge.io/gallery/3Dwebgl} 

begin{center}
begin{asy}
import three;
settings.render = 0;

size(0,100);
import solids;
currentlight=Viewport;

triple v=O;
real r=1;
real h=1.5;
triple axis=Y+Z;

// Optimized cylinder
surface cylinder=shift(v)*align(unit(axis))*scale(r,r,h)*unitcylinder;
draw(cylinder,green,render(merge=true));

// Skeleton
revolution r=cylinder(v,r,h,axis);
//draw(surface(r),green,render(merge=true));
draw(r,blue+0.15mm);
end{asy}
end{center}

end{document}

If you want only the vector image that is used as the poster image for the inactive 3D content as a stand-alone file, run asy with option -k (keep files) and look for example-1+0_0.pdf. This file can be included in other documents in the usual way using includegraphics:

asy -k example-1.asy