Comparing Trajectories

Autodesk 3ds Max Tutorials > Character Animation Tutorials > Biped Beyond the Basics > Working with Motion-Capture Data >

In this lesson, you'll learn to use trajectories to visualize and manipulate motion capture data.

Set up this lesson:

Open the file MyMotionCapture01.max.
This file was saved at the end of the last lesson.

Display and compare trajectories:

Select any part of the biped.
On the Motion Capture rollout, click Show Buffer Trajectory.
In the Biped rollout, open the expansion bar. In the Display group, click Trajectories.
In the Display group, click Preferences.
The Display Preferences dialog appears.
In the Trajectories group, turn on Bone Base. Click OK to close the dialog.
Select various parts of the biped to compare filtered and raw trajectories for each biped body part.
On the Display group, click Preferences again. On the Display Preferences dialog, turn off Show Entire Trajectory. Click OK.
Now the trajectories display only 50 frames before and after the current frame. Notice that the trajectories between the buffered and filtered data are very close.
On your hard disk, create your own directory for data that you filter. You can save this animation as a .bip file, using Save File on the Biped rollout.

TipThe 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 lesson, and then 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. Alternatively, you can 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.

Use 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 3ds Max.

Use 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.

Using High-Frequency Data and Looping