Pictures of discrete cyclides as featured in the first homework. Cyclides are examples of quartic surfaces. They are featured in our Math common room as models. You find other quartics there, one being the Kummer surface. The K3 surface, an example of a Calabi-Yau manifold is also a quartic x4+y4+z4+w4=0 but over the complex field. It is usually considered as a hypersurface in a three dimensional complex projective space.
Below is some Mathematica code to plot the surfaces. To the right is a picture of the cyclide in the math common room a few feet from Oliver's office in the 4th floor. There used to be a large collection of mathematical surfaces before the renovation. I photographed them in 2006. The Harvard graduate school of design photographed them again in 2012. You can find here an example of a Dupin Cyclide. And here a photo of the cycloid I made in 2006. God knows where most of these surfaces are now. But it is like in the "riders of the lost arc": "Harvard has top men working on it right now! Top men!" 

a=3; c=1; d=1; b=Sqrt[a^2-c^2]; R=1/(a-c Cos[u]*Cos[v]);
x=R(d(c - a*Cos[u]*Cos[v]) + b^2*Cos[u]);
y=R(b*Sin[u]*(a - d*Cos[v]));
z=R(b*Sin[v]*(c*Cos[u] - d));
ParametricPlot3D[{x,y,z},{u,0,2Pi},{v,0,2Pi}]
Oliver likes Cyclides because they are examples of Dehn-Sommerville manifold If d is changed to -1 there are two singularities. It has then the same Euler characteristic as a 2-sphere.