Compositing is the process of combining visual elements from multiple sources — live-action footage, CGI, graphics, and effects — into a single, unified image that appears as though everything was captured together.
Compositing is the art of seamlessly merging multiple visual elements into a single convincing image. It is the foundational discipline of visual effects, encompassing everything from simple tasks like placing a logo on a screen in a shot to complex work like integrating a CGI character into live-action footage with matching lighting, shadows, reflections, and atmospheric effects. The compositor's job is to make the impossible look real.
Professional compositing involves numerous technical skills: keying (extracting subjects from colored backgrounds), rotoscoping (hand-tracing elements frame by frame), color matching (ensuring all elements share the same color space and lighting), depth integration (adding atmospheric haze, focus matching, and perspective alignment), and motion matching (ensuring added elements move consistently with the camera). Tools like Nuke, After Effects, and Fusion are industry standards.
Even in projects that do not involve fantastical visual effects, compositing plays a practical role. Removing unwanted elements from shots (a visible crew member, an exit sign, a logo that needs clearing), adding screen content to devices filmed with blank or green screens, cleaning up backgrounds, or enhancing practical effects — all fall under compositing. Understanding compositing capabilities helps clients realize that many "impossible" shots are achievable in post-production, opening creative possibilities that might otherwise be dismissed.
Chroma keying is the compositing technique of removing a specific color (usually green or blue) from footage to create a transparent background, enabling replacement with any desired visual content.
Motion tracking is the process of analyzing footage to extract the movement data of specific points, objects, or the camera itself, allowing digital elements to be attached to or follow real-world motion.
Rotoscoping is the frame-by-frame process of manually tracing around elements in video footage to create precise mattes for isolation, compositing, or effect application.