The information below was graciously provided by VFX Supervisor Lesley Robson-Fostor. Click here for a video Q&A with Lesley on this topic.
In the modern filmmaking process, actors may be subjected to various types of scanning for multiple purposes, including visual effects, digital doubles, and performance capture. These scanning techniques capture detailed information about an actor's physical appearance, movements, and expressions. All of this uses some kind of artificial intelligence – but don’t get hung up on that term – in this instance it’s a very broad description of the digital work going on inside the computer to help make the images that get used in film and TV.
Applications of Scanning in Film and Television
These scanning techniques have various applications in film and television, including:
Digital Doubles: Creating realistic 3D models of actors for stunts, complex visual effects, or scenes that would be impractical to shoot with real actors. It would never be used as principal photography. Usually for deep background, crowds or dangerous stunts.
Virtual Production Animatic: Using digital doubles and environments to pre-visualize scenes or shoot entire sequences in a virtual environment. Only for planning and storyboard stages.
Makeup and Costuming: Designing and testing digital makeup and costumes before they are physically created. No performance work here – just modeling.
Performance Capture: Translating an actor's performance to a digital character, ensuring lifelike movement and expression in animated films or video games. Not for principle photography of humans but for creatures, aliens and animation.
Crowd tiling: this is where the same 100 people (or more, or less) are moved around inside a theater or stadium to create a full space. Also used in riots, baXles etc. Actor would be asked to sit or walk or fight in several different places and then in the post production phase – all the shots are joined together to give the impression of a crowd. This has been a standard technique for 50 years.
These technologies are continually evolving, providing filmmakers with increasingly sophisticated tools to enhance storytelling and create immersive visual experiences.
Here are the main types of scanning that actors might encounter:
3D Body Scanning – Actor stands inside the array of cameras (takes 5 mins at most). 3D body scanning captures a high-resolution, three-dimensional representation of an actor's entire body. This technique is used for creating digital doubles, costumes, and makeup effects. It involves the actor standing still while multiple cameras or laser scanners capture their body from all angles.
Full Body Scanning – This method uses a rig of cameras or lasers arranged around the actor to capture their body in a single scan. The data is then compiled to create a 3D model.
Partial Body Scanning – Sometimes only specific parts of the body, such as the head or hands, are scanned in higher detail for close-up shots or intricate digital effects.
Facial Scanning – Actor sits inside array of cameras (takes 5 mins at most). Focuses on capturing detailed 3D data of the actor's face. It is crucial for creating
realistic digital doubles, facial animation, and performance capture.
Photogrammetry – This method involves taking numerous high-resolution photographs of the actor's face from different angles. Software then stitches these images together to create a detailed 3D model. A visual effects professional will take photos with a regular camera 360 degrees around a person. This kind of photography can also be used to make ‘sprites’ – very distant digital doubles for
crowd work.
Motion Capture (Mo-Cap) – Records the actor's movements to be applied to digital characters. Actors wear suits fitted with markers that track their movements.
Optical Motion Capture – This system uses multiple cameras to track reflective markers placed on the actor's body. It is widely used due to its high precision and ability to capture complex movements.
Inertial Motion Capture – This method uses sensors attached to the actor's body to record motion. It is more portable and does not require an extensive camera setup, but it may be less accurate than optical systems.
Facial Motion Capture – Often combined with body motion capture, this technique captures the actor's facial expressions using markers or head-mounted cameras. It translates these expressions onto a digital character. This can also be done with an iPhone and a scanning LIDAR app. These scans are usually specific to each project, as requirements differ from production to production. So owning your scan from a particular project doesn’t mean you can pass it to another one.