(%11) hc:2*x*y+2*x*z=2;
(%i2) draw3d(enhanced3d=true,implicit(hc,x,-5,5,y,-5,5,z,-5,5));

% impsurf.tex :
%
documentclass[10pt,a4paper]{article}
usepackage{lmodern}
usepackage{subcaption}
usepackage[inline]{asymptote}
usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry}
begin{asydef}
settings.outformat="png";
settings.render=8;
import graph3;
import contour3;
currentlight=light(gray(0.8),ambient=gray(0.1),specular=gray(0.7),
                     specularfactor=3,viewport=true,dir(42,48));
pen bpen=rgb(0.75, 0.7, 0.1);
material m=material(diffusepen=0.7bpen
,ambientpen=bpen,emissivepen=0.3*bpen,specularpen=0.999white,shininess=1.0);
end{asydef}

%
begin{document}
%
begin{figure}
captionsetup[subfigure]{justification=centering}
    centering
      begin{subfigure}{0.49textwidth}
begin{asy}
size(200,0);
currentprojection=orthographic(camera=(9,10,4),up=Z,target=O,zoom=1);

// ellipsoid
real f(real x, real y, real z) {return (x^2)/(2^2) + (y^2)/(3^2) + (z^2)/(2^2)-1;}

draw(surface(contour3(f,(-3,-3,-3),(3,3,3),32)),m
     ,render(compression=Low,merge=true));

xaxis3(Label("$x$",1),-4,4,red);
yaxis3(Label("$y$",1),-4,4,red);
zaxis3(Label("$z$",1),-4,4,red);

end{asy}
%
caption{$(frac{x}{2})^2+(frac{y}{3})^2+(frac{z}{2})^2= 1$ (ellipsoid)}
label{fig:1a}
end{subfigure}
%
begin{subfigure}{0.49textwidth}
begin{asy}
size(200,0);
currentprojection=orthographic(camera=(9,4,4),up=Z,target=O,zoom=1);

// hyperbolic cylinder
real f(real x, real y, real z) {return 2*x*y + 2*x*z-1;}

draw(surface(contour3(f,(-3,-3,-3),(3,3,3),32)),m
     ,render(compression=Low,merge=true));

xaxis3(Label("$x$",1),-4,4,red);
yaxis3(Label("$y$",1),-4,4,red);
zaxis3(Label("$z$",1),-4,4,red);
end{asy}
%
caption{$2xy + 2xz = 1$ (hyperbolic cylinder)}
label{fig:1b}
end{subfigure}
caption{}
label{fig:1}
end{figure}
%
end{document}
%
% Process:
%
% pdflatex impsurf.tex
% asy impsurf-*.asy
% pdflatex impsurf.tex

documentclass[pstricks]{standalone}
usepackage{pst-solides3d,pst-math}
begin{document}

begin{pspicture}(-4,-4)(4,4)% the main 2D area
psset{lightsrc=viewpoint,viewpoint=50 -200 20 rtp2xyz,Decran=30}
pstVerb{/constA 1 def /constB 1 def }
defFunction[algebraic]{hcyl0}(u,v)
   { constA*SINH(u) }%                               x=f(u)
   { constB*COSH(u) }%                               y=f(u)
   { v }        %                               z=f(v)
defFunction[algebraic]{hcyl1}(u,v)
   { constA*SINH(u) }%                               x=f(u)
   { -constB*COSH(u) }%                               y=f(u)
   { v }        %                               z=f(v)
psSolid[object=surfaceparametree,base=-2 2 -3 3,
 fillcolor=red!40,function=hcyl0,linewidth=0.1pslinewidth,ngrid=25]
psSolid[object=surfaceparametree,base=-2 2 -3 3,
 fillcolor=red!40,function=hcyl1,linewidth=0.1pslinewidth,ngrid=25]
gridIIID[Zmin=-3,Zmax=3](-4,4)(-4,4)
end{pspicture}

end{document}