History of Motion Capture Technology

MocapHistory2009.ppt in the Workspace/Courses/AC760_Berezina_Sp09/

Motion Capture Pipeline

1. Action shotlist

Description of motion takes depending on the sequence of actions in animation or parameters varying from one take to another.

2. System Calibration

Establishing the capture volume and space origin.

Software: iQ

3. Capture

2D b/w images > 2d positions data >3d marker positions > marker trajectories

Software: iQ
Resulting Data File Types:C3D, V, CSV, TRC, CSM

Learn more about motion capture data file types

4. Labeling and Cleaning

Software: iQ
Resulting Data File Types:C3D, VSK (and V, CSV, TRC, CSM)

First take is a combination of a T-pose and Range Of Motion (ROM). Markers are labeled manually for each trajectory. Gaps are filled manually, based on marker trajectories.
VSK file is created based on subject's unique proportions.

For subsequent takes of actual planned movement, labeling and filling gaps is maximally automated with the use of VSK file.

5. Converting Positional Data to Rotational (markers to skeletal joints)

Software: MotionBuilder

Step 1

Resulting Data File Type: HIK

Attaching markers to an intermediate Actor.

Step 2

Resulting Data File Type: FBX

Constructing a skeleton (model is optional) in Maya or using existing model (with skeleton) in MotionBuilder. Skeleton is referred to as Character in MotionBuilder. Fitting the actor data to the skeleton.

Depending on the type of skeleton you use (depending on model design) the fitting may become a more elaborate process of retargeting.

6. Editing Motion and Final Output.

Option A.

Creating Control Rig in MotionBuilder.
1. Cutting and Blending multiple takes
2. Adding additional rig elements.Applying physics simulation (optional).
3. Baking the final animation to Maya skeleton.
4. Exporting sequence to Maya.
5. Rendering an animation sequence in Maya

Option B.

1. Baking motion to Maya skeleton.
2. Exporting sequence to Maya.
3. Adding additional rig elements (IK, constraints, deformers, etc)
4. Cutting and Blending multiple takes using Maya's Trax Editor.
5. Rendering an animation sequence in Maya

Mother and Daughter Duet from When I am Little Again
Charlotte Belland's Bird
Brian Windsor's Digital Puppets
Creature-runner

5a. Remapping Positional Data without Rotational Information

Software: Maya, 3DSM, etc

It is possible to use marker trajectories directly in 3d modeling and animation software (ie Maya) to construct and/or deform models.C3D file is converted to FBX in MotionBuilder.

Army (sheet of fabric dragged across a pile of props)
Human Landscape (hands tracing contours of a body)

Markers can serve as virtual "hooks" for attaching objects and more complex rigs.
Other examples from Landing Place
"Finger Painting" with mocap