Motion capture is the process of recording the movement of an actor or object using sensors and converting it into digital data. This data can then be used to create realistic animations in video games, movies, and other digital media.

Optical, magnetic, and inertial are all types of motion capture systems. Acoustic motion capture is not a real technology.

Optical motion capture systems are known for their high accuracy, as they use multiple cameras to track the movement of markers placed on the actor's body.

Hybrid motion capture systems, which combine optical and inertial sensors, are often used for capturing full-body movements, as they provide both high accuracy and freedom of movement.

Retargeting is the process of transferring motion capture data from one character or object to another. This allows animators to reuse motion capture data across multiple characters or objects.

.bvh (BioVision Hierarchy) is a common file format used for storing motion capture data. It is a text-based format that describes the hierarchical structure of the character's skeleton and the motion data for each joint.

Motion capture data often contains noise, which can result from sensor errors, environmental factors, or improper calibration. This noise can affect the accuracy and realism of the resulting animation.

Filtering is a common technique used to reduce noise in motion capture data. Filters can be applied to the raw data to remove unwanted noise while preserving important motion details.

Facial motion capture is the process of recording the movement of an actor's face using sensors and converting it into digital data. This data can then be used to create realistic facial expressions in digital characters.

Optical motion capture systems are often used for capturing facial expressions, as they can track the movement of small facial features with high accuracy.

One of the primary challenges associated with facial motion capture is achieving realistic facial expressions. It can be difficult to capture the subtle nuances of facial movement that convey emotions and expressions.

Blending is a technique commonly used to enhance the realism of facial motion capture data. Blending involves combining multiple motion capture takes or keyframes to create a smooth and natural transition between different facial expressions.

Facial rigging is the process of creating a digital representation of the actor's face, including the bones, muscles, and skin. This digital face is then used to transfer the motion capture data to the digital character, allowing it to replicate the actor's facial expressions.

.fbx (Filmbox) is a common file format used for storing facial motion capture data. It is a binary format that supports various data types, including skeletal animation, facial animation, and skinning data.

One of the primary challenges associated with motion capture data in video games is the limited range of motion. Motion capture data is typically recorded in a controlled environment, which may not fully represent the range of movements that a character needs to perform in a game.