Revision history [back]

Maybe you could use idea (2) for a Kummer surface like this (using Mathworld's equation for Kummer surface):

sage: var('mu2,x,y,z') # mu2 for mu^2
(mu2, x, y, z)
sage: la(mu2) = (3*mu2 - 1)/(3 - mu2)
sage: pqrs(w,x,y,z) = (w - z - sqrt(2)*x)*(w - z + sqrt(2)*x)*(w + z + sqrt(2)*y)*(w + z - sqrt(2)*y)
sage: Kmu(mu2,w,x,y,z) = (x^2 + y^2 + z^2 - mu2*w^2)^2 - la(mu2)*pqrs(w,x,y,z)
sage: def kummer(mu2,a,c=0,**kwds):
    f(x,y,z) = Kmu(mu2,1,x,y,z) - c
    P = implicit_plot3d(f,(x,-1*a,a),(y,-1*a,a),(z,-1*a,a),frame=False,**kwds)
    return P
....: 

sage: Inn = kummer(2,1.5,c=-.2,plot_points=150)
sage: Out = kummer(2,1.5,c=0,plot_points=150,color='red')
sage: (Inn+Out).show(viewer='tachyon')