Complete capture of deep cavities and thin walls

What makes it hard

A skull is an extreme case of geometric complexity. The orbits and nasal cavity are deep recesses. The zygomatic arch and nasal bone become almost as thin as a blade edge. The overall shape also causes heavy self-occlusion.

For a line-of-sight sensor, light enters a deep cavity but has difficulty coming out, so the return is weak. Thin edges produce “flying pixels”, which are false points between foreground and background. Bone is also translucent. Light scatters below the surface before it returns, which blurs the depth decision.

What we measured

2,272,452 raw points, the largest count of these captures. The structure inside the orbits, the thin edge of the zygomatic arch and the detail of the teeth all survive.

Statistical outlier and small-cluster removal dropped about 5% of the points. Most of these were flying pixels along thin edges. That proportion itself shows how hard thin edges are to capture.