Tri-Di or 3-V (short for tri-dimensional or three-dimensional visual) was a form of entertainment technology popular from the mid 21st century and into the 23rd century. It involved the recording and projection of a subject as a holographic image that could be viewed from multiple angles. The technology was originally referred to as holovision, and in the 2040s, was widely available, even on the isolated agronomy stations in the Pacific Ocean. (TOS novel: Strangers from the Sky) Tri-Di shows were often viewed by crewmen on the USS Enterprise in 2267. (TOS novel: Mission to Horatius)