Artificial intelligence startup Runway on Monday announced Gen 4.5, a new video model that outperforms similar models from Google and OpenAI in an independent benchmark.Gen 4.5 allows users to generate high-definition videos based on written prompts that describe the motion and action they want. Runway said the model is good at understanding physics, human motion, camera movements and cause and effect.The model holds the No. 1 spot on the Video Arena leaderboard, which is maintained by the independent AI be ...