Random Gaussian cubic surface Seed: 165 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = 0.377 x*z^2 +0.128 y*z^2 +0.0144 z^2 -0.163 x^2*z +0.261 x*y*z -0.106 x*z -0.381 y^2*z -0.0976 y*z -0.475 z +0.168 x^3 -0.0193 x^2*y +0.337 x^2 -0.126 x*y^2 +0.0455 x*y +0.23 x +0.342 y^3 -0.033 y^2 -0.094 y +0.122 1
Affine cubic: f(x,y,z) = 0.377 x*z^2 +0.128 y*z^2 +0.0144 z^2 -0.163 x^2*z +0.261 x*y*z -0.106 x*z -0.381 y^2*z -0.0976 y*z -0.475 z +0.168 x^3 -0.0193 x^2*y +0.337 x^2 -0.126 x*y^2 +0.0455 x*y +0.23 x +0.342 y^3 -0.033 y^2 -0.094 y +0.122 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].