Random Gaussian cubic surface Seed: 392 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = -0.00331 x*z^2 -0.136 y*z^2 +0.0978 z^2 +0.206 x^2*z +0.307 x*y*z +0.242 x*z +0.203 y^2*z +0.318 y*z +0.0475 z +0.107 x^3 +0.316 x^2*y +0.287 x^2 -0.0816 x*y^2 -0.404 x*y +0.0812 x -0.434 y^3 -0.0241 y^2 +0.261 y +0.0691 1
Affine cubic: f(x,y,z) = -0.00331 x*z^2 -0.136 y*z^2 +0.0978 z^2 +0.206 x^2*z +0.307 x*y*z +0.242 x*z +0.203 y^2*z +0.318 y*z +0.0475 z +0.107 x^3 +0.316 x^2*y +0.287 x^2 -0.0816 x*y^2 -0.404 x*y +0.0812 x -0.434 y^3 -0.0241 y^2 +0.261 y +0.0691 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].