Random Gaussian cubic surface Seed: 23 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = 0.134 x*z^2 +0.0527 y*z^2 -0.0141 z^2 -0.562 x^2*z +0.105 x*y*z -0.515 x*z +0.22 y^2*z +0.147 y*z +0.201 z +0.201 x^3 +0.0723 x^2*y -0.13 x^2 -0.0744 x*y^2 +0.365 x*y -0.141 x -0.0553 y^3 -0.176 y^2 -0.125 y -0.0743 1
Affine cubic: f(x,y,z) = 0.134 x*z^2 +0.0527 y*z^2 -0.0141 z^2 -0.562 x^2*z +0.105 x*y*z -0.515 x*z +0.22 y^2*z +0.147 y*z +0.201 z +0.201 x^3 +0.0723 x^2*y -0.13 x^2 -0.0744 x*y^2 +0.365 x*y -0.141 x -0.0553 y^3 -0.176 y^2 -0.125 y -0.0743 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 7 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].