Luma, an AI video and 3D model company backed by a16z, has launched a new model named Ray3 Modify. This tool enables users to alter existing video footage by supplying character reference images, which maintain the original performance's integrity. Additionally, creators can input a start and an end frame to help the model produce smooth transitional sequences.

On Thursday, the company highlighted that Ray3 Modify addresses key challenges for creative studios, specifically in preserving human performances during AI-driven editing and effects generation. The startup emphasized that the model adheres more closely to the input footage, allowing studios to leverage human actors for creative or branded content. According to Luma, Ray3 Modify keeps the actor's original motion, timing, eye line, and emotional delivery intact while transforming the scene.

With this model, users can provide a character reference to transform the original footage, converting the human actor's appearance into that of the specified character. This reference also helps creators maintain consistent details like costumes, likeness, and identity throughout the production. Furthermore, by supplying start and end reference frames, users can generate videos that guide transitions or control character movements and behavior, ensuring continuity between scenes.

Amit Jain, co-founder and CEO of Luma AI, stated, "Generative video models are incredibly expressive but also hard to control. Today, we are excited to introduce Ray3 Modify that blends the real-world with the expressivity of AI while giving full control to creatives. This means creative teams can capture performances with a camera and then immediately modify them to be in any location imaginable, change costumes, or even go back and reshoot the scene with AI, without recreating the physical shoot."

Luma has made the new model available through its Dream Machine platform. The company, which competes with firms like Runway and Kling, initially introduced video modification features in June 2025. This release follows a significant $900 million funding round announced in November, led by Saudi Arabia's Public Investment Fund-owned AI company Humain. Existing investors, including a16z, Amplify Partners, and Matrix Partners, also contributed to the round. Additionally, the startup is collaborating with Humain to develop a 2GW AI cluster in Saudi Arabia.