Random Gaussian cubic surface Seed: 376 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = 0.168 x*z^2 -0.136 y*z^2 +0.184 z^2 +0.21 x^2*z +0.35 x*y*z +0.0508 x*z -0.0878 y^2*z +0.425 y*z +0.203 z +0.0508 x^3 -0.136 x^2*y +0.00682 x^2 +0.0641 x*y^2 +0.0242 x*y +0.2 x -0.118 y^3 -0.567 y^2 -0.289 y -0.19 1
Affine cubic: f(x,y,z) = 0.168 x*z^2 -0.136 y*z^2 +0.184 z^2 +0.21 x^2*z +0.35 x*y*z +0.0508 x*z -0.0878 y^2*z +0.425 y*z +0.203 z +0.0508 x^3 -0.136 x^2*y +0.00682 x^2 +0.0641 x*y^2 +0.0242 x*y +0.2 x -0.118 y^3 -0.567 y^2 -0.289 y -0.19 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].