Digital or practical humanoid figures—androids, robots, clones—for scenes live actors can't perform. Motion capture or full CGI.
If you need a scene where a character falls out of a window, survives an explosion, or simply doesn't age — you can't avoid artificial humans. These are digitally or practically constructed figures that are either entirely synthetic or based on motion capture data from real actors. The difference lies in authenticity and budget: motion capture costs, but delivers movements with genuine organic quality. Pure CGI characters give you absolute control, but can appear plasticky faster if the animation isn't refined obsessively.
In practice, you distinguish three approaches. Digital Doubles — exact 3D scans of actors — are the method of choice when you need the same character in extreme action scenes. The DoP shoots the real actor's performance, the VFX supervisor creates a high-resolution facial model, and in post-production, the double is seamlessly integrated. Androids and robots allow you more leeway: surfaces like silicone or metal forgive minor animation errors more easily than skin. Fully synthetic characters — think of alien beings or science fiction settings — often work better because the audience has less material for comparison and your animation doesn't have to fight against the "uncanny valley."
On set, you need clear guidelines: Where will you be greenscreening? What focal length will the camera use for the digital double? If motion capture is involved, your markers need precise placement, and the actor must perform in a clean suit — without clothing that will be composited later. This leads to problems with drapery and contact. A common mistake: filming too little motion overhead. The VFX department needs more frames with variation to create natural irregularity.
Lighting is critical. Artificial humans are unforgiving with incorrect shadows and specular reflections — any small incongruity with your lighting setup will be visible. Shoot at a higher bitrate if possible, and maintain consistent light direction and temperature. In the edit, you'll quickly notice if the character stands out from the rest of the scene. The best CGI works because it makes you forget that it's not a real person.