Luma, the a16z-backed AI video and 3D model company, released a new model called Ray3 Modify that allows users to modify existing footage by providing character reference images that preserve the performance of the original footage. Users can also provide a start and an end frame to guide the model to generate transitional footage. The company said Thursday the Ray3 Modify model solves the problems of preserving human performance while editing or generating effects using AI for creative studios....