Random Gaussian cubic surface Seed: 38 (Gaussian coefficient and line-tracking seed)
Cubic: f(x,y,z) = 0.338 x*z^2 +0.0322 y*z^2 +0.063 z^2 +0.204 x^2*z +0.105 x*y*z +0.357 x*z -0.272 y^2*z +0.211 y*z +0.0214 z +0.305 x^3 +0.297 x^2*y +0.211 x^2 -0.125 x*y^2 -0.12 x*y +0.0411 x -0.112 y^3 -0.441 y^2 -0.334 y +0.0808 1
Affine cubic: f(x,y,z) = 0.338 x*z^2 +0.0322 y*z^2 +0.063 z^2 +0.204 x^2*z +0.105 x*y*z +0.357 x*z -0.272 y^2*z +0.211 y*z +0.0214 z +0.305 x^3 +0.297 x^2*y +0.211 x^2 -0.125 x*y^2 -0.12 x*y +0.0411 x -0.112 y^3 -0.441 y^2 -0.334 y +0.0808 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].