Random Gaussian cubic surface Seed: 346 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = 0.3 x*z^2 -0.482 y*z^2 -0.239 z^2 -0.414 x^2*z +0.195 x*y*z +0.0526 x*z -0.02 y^2*z +0.218 y*z -0.0978 z -0.307 x^3 +0.0317 x^2*y +0.0919 x^2 -0.117 x*y^2 +0.0966 x*y +0.0495 x +0.283 y^3 -0.00608 y^2 -0.00728 y +0.376 1
Affine cubic: f(x,y,z) = 0.3 x*z^2 -0.482 y*z^2 -0.239 z^2 -0.414 x^2*z +0.195 x*y*z +0.0526 x*z -0.02 y^2*z +0.218 y*z -0.0978 z -0.307 x^3 +0.0317 x^2*y +0.0919 x^2 -0.117 x*y^2 +0.0966 x*y +0.0495 x +0.283 y^3 -0.00608 y^2 -0.00728 y +0.376 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].