It's been around for decades, but, unlike regular 3D, virtual reality (VR) has yet to make a big impact in the movie industry, something a maker of Hollywood animation believes he can change – if the films are good enough.

Eric Darnell, who co-wrote and directed the Madagascar movies, showed his own VR film at the Venice Film Festival this week, Crow: The Legend, in which the viewer is immersed in the story of a mythical bird that has to fly to the sun to bring back warmth to the Earth.

With a voice cast that includes Oprah Winfrey, John Legend and Crazy Rich Asians star Constance Wu, Crow is hardly an amateur affair, but Darnell's Baobab Studios will be giving the movie away rather than selling it, as a way to generate interest in the medium.

"I don't expect it's going to be today or six months even," he said of when VR might go mainstream.

"The technology has to get better, headsets have to get cheaper, the content has to get better and that's at least as important as anything else," Darnell told Reuters.