carter-bust

Turns a full-resolution 3D scan of Carter's own head, about a million vertices at life size, into a watertight bust ready to print. The scripts run inside Blender with no window. One fits the scan to an earlier 16k-vertex copy that had already been stood upright, by ICP with scale from 24 starting orientations found by PCA, which also brings it down about 2.44 times to print size. The next rebuilds the surface from scratch, so holes, ragged edges and the missing back of the head all close in one pass.

The rebuild

A Poisson surface reconstruction written in numpy. The scan's oriented face areas are splatted onto a grid of 0.55 mm voxels, the Poisson equation is solved with FFTs, and the surface is taken at the level the scan itself sits on. Marching tetrahedra turn that into a mesh, only the largest piece is kept, and eight passes of Taubin smoothing take out the marching-tetrahedra ripple.

Smoothing loses detail, so the original scan is pressed back onto the new surface wherever it lies within a couple of millimetres, faded out near big holes so no seam shows. Then the mesh is decimated, cut flat at the base, given the scan's texture as vertex colors, and stood up facing Blender's front view.

A verify script checks the result is a clean solid (boundary and non-manifold edges, degenerate faces, volume, size, connected components) and measures how far 60,000 sampled scan points lie from the new surface, at the median, 75th and 90th percentiles.

Stated honestly

The scripts, a 49 MB STL and before-and-after renders all date from one evening in October 2026. The verify numbers from that run were not kept, the source scan is not in the folder, and nothing records whether the bust has been printed.