**O. Aichholzer, W. Aigner, F. Aurenhammer, and B. Jüttler**

We propose a novel approach for the medial axis approximation of triangulated
solids by using a polyhedral unit ball instead of the standard Euclidean
unit ball. By this means, we compute the exact medial axis of a
triangulated solid with respect to a piecewise linear (quasi-)metric
. The obtained representation of by the medial axis transform
allows for a convenient computation of the trimmed offset of
with respect to . All calculations are performed within the
field of rational numbers, resulting in a robust and efficient implementation
of our approach. Adapting the properties of provides an easy way to
control the level of details captured by the medial axis, making use of the
implicit pruning at flat boundary features.