> #The first animation is goes from a hyperaboloid of two sheets through a cone to a hyperaboloid of one sheet.
> with(plots);
> a:=seq(implicitplot3d(x^2+y^2-z^2 -t/6,x=-3..3,y=-3..3,z=-3..3,orientation=[0,90],numpoints=2000),t=-12..12):
> display3d(a,insequence=true);
> # The second animation shows how a hyperaboloid of one sheet looks more and more like a cone the farther away you get.
> a:=seq(implicitplot3d(x^2+y^2-z^2 -1/t,x=-3..3,y=-3..3,z=-3..3,orientation=[0,90],numpoints=3000),t=1..10):
> display3d(a,insequence=true);
>