Investigating The Use Of Primes In Hashing For Volumetric Data

Traditional hashing methods used to store 3D volumetric data utilise large prime numbers. The intention of this is to achieve well-distributed hash addresses to minimise addressing collisions. Hashing is an attractive method to store 3D volumetric data, as it provides simple method to store, index and retrieve data. However, implementations fail to provide theoretical support as to why they utilise large primes which act to create a hash address through randomising key values. Neither is it specified what a "large" prime is. 3D data is inherently well-distributed as each coordinate in 3D space is already unique. It is thus investigated in this paper whether this randomisation through the use of large primes is necessary. The history of the use of primes for hashing 3D data is also investigated, as is whether their use has persisted due to habit rather than due to methodical investigation.