Biped motion (BIP) files have a .bip file name extension. They save all information about biped motion: footsteps, keyframe settings including limb rotation, the scale of the biped, and the active gravity (GravAccel) value. IK Blend values for the keys and Object Space settings are also saved.
IK objects, props and other objects in the scene can also be saved with the BIP file.
There are several ways to create or acquire .bip files:
- By loading one of the sample animation files that come with 3ds Max. Refer to the Installation Guide for more details.
- By creating your own animation with footsteps or freeform methods, and saving the animation with the
Save button in the Biped rollout. See the procedures that follow. - By loading and filtering a motion capture file, then saving the animation with the Save button in the Biped rollout. See Filtering Motion-Capture and Marker Data.
When you save a Motion Mixer (MIX) file or a Motion Flow Editor (MFE) file, the paths to the referenced BIP files are also saved. If these paths are broken (for example, if the BIP files have been moved or renamed), a Missing Motion Mixer Files dialog or Missing Motion Flow Files dialog, respectively, opens listing the missing files. To rectify this, open the Asset Tracking dialog and set a new path for the files.
Procedures
To load biped motion from an existing BIP file:
-
Select the biped you want to animate, and go to the 
Motion panel. - On the Biped rollout, make sure you are not in Figure mode, and click
(Load File). Note: When Figure mode is active, the Load File option loads figure (FIG) files. Anything done in Figure mode changes the basic shape and structure of the biped. When Figure mode is turned off, the Load File tool loads BIP files, which animate the figure. - In the file dialog, choose the BIP motion file to load, and then click OK.
- The biped repositions itself in the scene, as it assumes the initial position of the animation file. You might need to use Zoom Extents to see the biped after it is repositioned. Tip: The Biped keyboard shortcut Alt+R sets the animation range to that of the currently selected biped. Since the length of the animation can change after loading a BIP file, this keystroke can be useful. To use it, make sure that the Keyboard Shortcut Override Toggle is active.
To save animation you have created or imported to a BIP file:
- Animate the biped with footsteps or freeform animation (or both).
- Select the biped that has the animation you want to save, and go to the Motion panel.
- On the Biped rollout, make sure you are not in Figure mode, and click (Save File).
- In the file dialog, enter a name for the motion file, and then click OK.