Boy's Surface

A 3-D rendering of Boy's surface. The design starts in Sage, export to X3D (resulting file included), then import X3D into Blender. In Blender, edit to remove artifacts Sage leaves behind (like a cube of lines around the figure, which can also be removed in Sage using option "frame=False" as seen in Sage code below), then "thicken" the surface so that Cura can recognize it as a solid object:

1. select Properties -> Modifiers (wrench icon) -> Add Modifier -> Solidify
2. set Thickness to 0.1 and click Apply

Now export to STL, then import STL into Cura. In Cura, scale (because graph units in Sage become millimeters in Cura) and situate figure on print platform, then export STL again to form the STL thing file here.

Here is the Sage code to generate the figure:

p,t=var('p,t')
u=cos(t)*sin(p)
v=sin(t)*sin(p)
w=cos(p)
x=(1/2)*((3*u^2-1)+2*v*w*(v^2-w^2)+u*w*(u^2-w^2)+u*v*(v^2-u^2))
y=(sqrt(3)/2)*((v^2-w^2)+u*w*(w^2-u^2)+u*v*(v^2-u^2))
z=(u+v+w)*(