An algorithm for generating unstructured tetrahedral meshes of arbitrarily
shaped three-dimensional regions is described. The algorithm works for regi
ons without cracks, as well as for regions with one or multiple cracks. The
algorithm incorporates aspects of well known meshing procedures, hilt incl
udes some original steps. It uses an advancing front technique, along with
an octree to develop local guidelines for the size of generated elements. T
he advancing front technique is based on a standard procedure found in the
literature, with two additional steps to ensure valid volume mesh generatio
n for virtually any domain. The first additional step is related to the gen
eration of elements only considering the topology of the current front and
the second additional step is a back-tracking procedure with face deletion,
to ensure that a mesh can be generated even when problems happen during th
e advance of the front. To improve mesh quality (as far as element shape is
concerned), an a posteriori local mesh improvement procedure is used The p
erformance of the algorithm is evaluated by application to a number of real
istically complex, cracked geometries.