Comparing Trajectories

Working with Motion-Capture Data

Importing Prop Data

 

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

Using High-Frequency Data and Looping

With high-frequency motion, such as sprinting, you can lose the nuances of the motion if you use the default filter settings. In this lesson, you will minimize key reduction on the legs of a sprinter so the legs follow the raw motion data more closely. You'll also learn to loop a motion file in the Motion Capture Parameters dialog.

Set up for this lesson:

• Reset 3ds Max.

Load a CSM file:

1. In the Front viewport, create a biped.
2. On the Motion panel, in the Motion Capture rollout, click Load Motion Capture File. Choose .csm as the file type.
3. Open jez.sprint.csm.

   The Motion Capture Conversion Parameters dialog is displayed.

4. Choose On for Footstep Extraction, and Use Key Reduction for Conversion. Click OK.

   The clip loads but has no footsteps.

5. In the Biped rollout, open the expansion bar. In the Display group, switch from Objects to Bones on the flyout.
6. In the Motion Capture rollout, turn on Show Buffer.

   The red stick figure represents the raw motion capture data. The other stick figure represents the filtered data. Note that you can’t use In Place mode with Show Buffer.

Compare the data:

1. Use Alt+W to maximize the Left viewport.
2. Click Play Animation.

   The filtered data lags behind the raw data in the feet, making the sprint look more like a fast shuffle. However, this is hard to see because of fast playback and the key bracketing.

   

3. Right-click the Play Animation button. In the Time Configuration dialog, in the Playback group, turn on Real Time and 1/4x Speed to slow down the motion. Turn off key bracketing by choosing Customize > Preferences > Animation > Key Bracket Display group > None.
4. In the Motion Capture rollout, click Convert From Buffer.

   The motion capture buffer contains raw motion capture data. You’ll enter parameters to correct the lagging and to extract footsteps.

   In the Motion Capture Conversion Parameters dialog, choose On for Footstep Extraction and Use Key Reduction for Conversion.

5. In the Footstep Extraction group, set Extraction Tolerance to 1.23.
6. In the Key Reduction Settings group, change the Minimum Key Spacing for both legs to 1. Click OK.

   The filtered legs match the raw legs during the sprint. The legs have a key at almost every frame, but the rest of the biped has key reduction.

   

Loop a motion capture file:

1. In the Motion Capture rollout, click Load Motion Capture File. Choose .csm as the file type.
2. Open jez.sprint.csm.

   The Motion Capture Conversion Parameters dialog is displayed. All the settings on this dialog should be the ones you entered previously.

3. In the Load Frames group, turn on Loop and enter 1 in the Loop field. Click OK.

   The sprinting motion is looped, creating a longer sprinting period. You can also loop a motion in the Motion Flow Graph with similar results.