 
Summary: The Power Crust
Nina Amenta Sunghee Choi Ravi Krishna Kolluri £
University of Texas at Austin
Figure 1. Laser range data, the reconstructed watertight polygonal model, and its simplified medial axis.
Abstract
The power crust is a construction which takes a sample of points
from the surface of a threedimensional object and produces a sur
face mesh and an approximate medial axis. The approach is to first
approximate the medial axis transform (MAT) of the object. We
then use an inverse transform to produce the surface representation
from the MAT.
This idea leads to a simple algorithm with theoretical guarantees
comparable to those of other surface reconstruction and medial axis
approximation algorithms. It also comes with a guarantee that does
not depend in any way on the quality of the input point sample. Any
input gives an output surface which is the `watertight' boundary of
a threedimensional polyhedral solid: the solid described by the
approximate MAT. This unconditional guarantee makes the algo
rithm quite robust and eliminates the polygonalization, holefilling
or manifold extraction postprocessing steps required in previous
