NAPSAC generates fractures as a combination of deterministic and random fractures. For random fractures a classification into sets is used. The basis for classifying these sets can be according to orientation, spatial location or flow properties.
There are four possible random process available in NAPSAC for locating fractures. These are:

• uniform spatial process (Poisson point process);
• clustering fractures around deterministic fractures;
• clustering fractures around a random set of fractures;
• clustering fractures around a random points.