size(7.5cm,0);
import graph3;

currentprojection=perspective(camera=(5,3,3));

path3 p1=shift(-1,-1,0)*scale3(2)*unitsquare3,
      p2=scale3(.25)*unitcircle3;

path3[] p3=shift(.5,.5,0)*p2
           ^^shift(-.5,-.5,0)*p2
           ^^shift(.5,-.5,0)*p2
           ^^shift(-.5,.5,0)*p2;

draw(p1,1bp+red);
draw(p3,1bp+blue);

draw(surface(reverse(p1)^^p3,planar=true),white+opacity(.5));

limits(-1.5X-1.5Y-.5Z,1.5X+1.5Y+Z);
xaxis3("$x$",Arrow3);
yaxis3("$y$",Arrow3);
zaxis3("$z$",Arrow3);