Random Gaussian cubic surface Seed: 269 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = 0.164 x*z^2 -0.124 y*z^2 +0.271 z^2 -0.0145 x^2*z +0.208 x*y*z +0.507 x*z +0.353 y^2*z +0.141 y*z -0.0412 z +0.203 x^3 -0.286 x^2*y -0.18 x^2 +0.26 x*y^2 -0.0707 x*y -0.0241 x +0.118 y^3 -0.17 y^2 +0.173 y +0.369 1
Affine cubic: f(x,y,z) = 0.164 x*z^2 -0.124 y*z^2 +0.271 z^2 -0.0145 x^2*z +0.208 x*y*z +0.507 x*z +0.353 y^2*z +0.141 y*z -0.0412 z +0.203 x^3 -0.286 x^2*y -0.18 x^2 +0.26 x*y^2 -0.0707 x*y -0.0241 x +0.118 y^3 -0.17 y^2 +0.173 y +0.369 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].