A spider web is mostly a 2D drawing. A 3D-printable bowl is a 3D shape. The trick in this post is to draw the web as a flat CrossSection , extrude it straight down, and subtract it from a bowl shell. The same trick works for any pattern: leaves, stars, bats. Everything uses manifold3d and plain Python. 1. A bowl from two spheres A shallow bowl is a spherical cap. For a cap of rim radius Rb and height H , the sphere radius is Rs = (Rb^2 + H^2) / (2 H) . from mani...