When Mats Steen died of Duchenne muscular dystrophy at the age of 25 in 2014, he left behind the passwords to a rich life that he had lived online as his condition worsened, much of it in the Starlight guild of the multiplayer game “World of Warcraft.” His family was unaware that as his avatar, Ibelin, Mats had a wide array of friends — but they let director Benjamin Ree (“The Painter and the Thief”) document their son’s life through home movies and interviews but also through detailed animation that re-creates his world inside the video game.

Ree’s film, “The Remarkable Life of Ibelin,” won audience and directing awards at this year’s Sundance Film Festival and landed a deal with Netflix.

Benjamin Ree at the Tribeca Film Festival (Getty Images)

I understand you had a connection with Mats’ family that led you to make this film.

Yeah. Mats’ uncle was my main teacher at school.