Most AI video tools can put a person in a frame. The hard part is making that person move like a real body: feet that stay planted, weight that shifts from leg to leg, fingers that close around an object, and a face and outfit that stay the same. We gave the same three tasks to four models: walk and turn, sit down and stand up, pick up a glass and put it back. Copying motion from a video was tested separately.
Looking for prompting techniques rather than a tool comparison? See How to Make AI People Move Realistically.
Why Human Motion Is the Hardest Problem in AI Video
Getting a convincing environment right is mostly a texture problem. Getting an object right is mostly a geometry problem. Getting a person to move convincingly is all three problems at once, plus physics, plus performance, plus frame-to-frame consistency. The weight has to load before the action and release after it, and all of that has to hold across every frame without the model defaulting to an average.


