Hollywood director James Cameron says all forms of entertainment will eventually be 3D - because "that's how we see the world."

The director made the claims despite 3D movie revenues faltering and consumer indifference to 3D television content.

Mr Cameron, who has directed and produced some of the biggest grossing movies in Hollywood - including 3D hit Avatar - argues 3D has been one of the milestones of cinema, along with sound and colour.

He spoke to the BBC's North America correspondent Richard Taylor.