Random Gaussian cubic surface Seed: 258 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = 0.201 x*z^2 +0.00957 y*z^2 +0.0214 z^2 -0.22 x^2*z -0.135 x*y*z -0.0103 x*z -0.097 y^2*z +0.0213 y*z +0.00431 z -0.464 x^3 +0.0991 x^2*y -0.162 x^2 +0.456 x*y^2 +0.0413 x*y +0.0851 x +0.0162 y^3 -0.64 y^2 -0.0608 y -0.0234 1
Affine cubic: f(x,y,z) = 0.201 x*z^2 +0.00957 y*z^2 +0.0214 z^2 -0.22 x^2*z -0.135 x*y*z -0.0103 x*z -0.097 y^2*z +0.0213 y*z +0.00431 z -0.464 x^3 +0.0991 x^2*y -0.162 x^2 +0.456 x*y^2 +0.0413 x*y +0.0851 x +0.0162 y^3 -0.64 y^2 -0.0608 y -0.0234 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].