Ian Sansavera, a software architect at a New York startup called Runway AI, typed a short description of what he wanted to see in a video. “A tranquil river in the forest,” he wrote.
Less than two minutes later, an experimental internet service generated a short video of a tranquil river in a forest. The river’s running water glistened in the sun as it cut between trees and ferns, turned a corner and splashed gently over rocks.
Runway, which is about to open its service to a small group of testers, is one of several companies building artificial…