Luma, the AI video and 3D modeling company backed by Andreessen Horowitz (a16z), has unveiled a new AI model called Ray3 Modify, designed to let users generate and modify video footage using just a start and end frame. The model enables creators to preserve the original performance of human actors while transforming scenes, characters, or environments with precision. Ray3 Modify allows users to input a character reference image to alter the appearance of a person in existing footage—such as changing costumes, facial features, or overall likeness—while maintaining the original motion, timing, eye line, and emotional delivery. This capability is especially valuable for creative studios that want to retain the authenticity of a live performance while making visual changes. In addition, users can provide a start and end frame to guide the model in generating smooth, realistic transitional footage. This feature gives creators full control over character movement, behavior, and scene transitions, ensuring continuity across shots. According to Luma, the model excels at following the input footage closely, making it ideal for reshooting scenes or adjusting settings without requiring a physical shoot. “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,” said Amit Jain, co-founder and CEO of Luma AI. The model is now available to users through Luma’s Dream Machine platform. This release follows the company’s earlier introduction of video modification tools in June 2025, positioning Luma as a key player in the competitive generative video space alongside companies like Runway and Kling. The launch comes on the heels of a major $900 million funding round led by Humain, a Saudi Arabia-based AI company owned by the Public Investment Fund. Additional investors in the round include a16z, Amplify Partners, and Matrix Partners. Luma also plans to build a 2-gigawatt AI cluster in Saudi Arabia in collaboration with Humain, signaling a significant expansion of its infrastructure and global ambitions.