Random Gaussian cubic surface Seed: 380 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = 0.237 x*z^2 -0.0589 y*z^2 +0.201 z^2 +0.121 x^2*z -0.172 x*y*z -0.115 x*z +0.293 y^2*z -0.0176 y*z -0.0834 z +0.102 x^3 -0.472 x^2*y +0.0249 x^2 -0.0757 x*y^2 -0.156 x*y -0.152 x +0.0605 y^3 -0.346 y^2 -0.0306 y -0.582 1
Affine cubic: f(x,y,z) = 0.237 x*z^2 -0.0589 y*z^2 +0.201 z^2 +0.121 x^2*z -0.172 x*y*z -0.115 x*z +0.293 y^2*z -0.0176 y*z -0.0834 z +0.102 x^3 -0.472 x^2*y +0.0249 x^2 -0.0757 x*y^2 -0.156 x*y -0.152 x +0.0605 y^3 -0.346 y^2 -0.0306 y -0.582 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].