Random Gaussian cubic surface Seed: 60 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = -0.246 x*z^2 -0.0848 y*z^2 +0.19 z^2 -0.293 x^2*z -0.299 x*y*z +0.252 x*z +0.277 y^2*z +0.409 y*z -0.0414 z +0.222 x^3 +0.126 x^2*y +0.0557 x^2 +0.19 x*y^2 +0.0708 x*y +0.421 x +0.165 y^3 -0.113 y^2 +0.192 y +0.22 1
Affine cubic: f(x,y,z) = -0.246 x*z^2 -0.0848 y*z^2 +0.19 z^2 -0.293 x^2*z -0.299 x*y*z +0.252 x*z +0.277 y^2*z +0.409 y*z -0.0414 z +0.222 x^3 +0.126 x^2*y +0.0557 x^2 +0.19 x*y^2 +0.0708 x*y +0.421 x +0.165 y^3 -0.113 y^2 +0.192 y +0.22 1
Shadow: the quartic B(x,y)^2 - 4 A(x,y) C(x,y) = 0 is drawn on the z=-4 xy-plane in the same 3D scene. The translucent ruled curtain rises upward from the shadow to the ramification curve where the lifted point has z >= -2 and lies above the displayed projection plane. The 3 real projected lines on the xy-plane are bitangents found from the projective lines on the cubic surface. Same-color transparent line projection cones are included but hidden by default; use the page toggle to show them.
Viewing box: axis ranges are [-4, 4].