Tutorial 6: Working with Motion Capture Data

Lesson 2: Comparing Trajectories

This lesson continues from the end of Lesson 1.


  1. On the Motion Capture rollout, click Show Buffer Trajectories.

  2. On the Display rollout, click Trajectories.

  3. On the Display rollout, click Display Preferences. In the Trajectories group, select Bone Base.

  4. Close the Display Preferences dialog.

  5. Select various parts of the biped to compare filtered and raw trajectories for each biped body part.

  6. On the Display rollout, click Display Preferences. In the dialog's Trajectories area, turn off Show Entire Trajectory. Now the trajectories display only 50 frames before and after the current frame.

    The trajectories between the buffered and filtered data are very close. Create your own directory for data that you will filter. Save this animation as a .bip file, if you like.

The default filter settings work well in many cases, but information may be lost in motion capture files that contain a lot of high-frequency motion. There are a number of ways to work with such files. One is to filter the file normally, as you did in this tutorial, and paste the missing information using Paste from Buffer on the Motion Capture rollout.

You can also change Tolerance and Key Spacing parameters for less key reduction, or import a motion capture file with no key reduction and add a layer on the Layers rollout. This is an easy way to make changes to a file that contains keys at every frame.

Using Calibration Controls

Motion Capture calibration controls (the bottom row of buttons on the Motion Capture rollout) are active only if a raw motion capture file is imported with no key reduction. They are used primarily to calibrate marker (.csm) files, although they work with all raw motion capture data.

Marker files represent raw marker position data directly from a motion capture device, and typically require more work than the .bvh or .bip motion capture files that ship with character studio.

Using Marker Files

You can manage biped size and limb position relative to the markers with the two main calibration functions on the Motion Capture rollout: Talent Figure Mode and Adjust Talent Pose. The size and limb offsets are saved as .fig and .cal files, respectively. These files, as well as a marker name (.mnm) file, can be loaded prior to importing a motion capture file to apply the size and limb offsets to marker files requiring the same adjustment.