Once you've worked with
the Motion Mixer to create an animated sequence for the biped, there
are several ways to work with the finished mix.
If you want to work with
the mix on the current biped (rather than a another biped in the
scene), you have several options:
- If you're satisfied with the animation
as it is, you can turn on (Mixer
Mode) on the
rollout to display the mix on the biped,
and simply render the scene.
- If transitions between different foot/leg
motions have created small pops or jerks near the transition area,
you will want to create a
the biped and check the mixdown before copying it to the biped.
A mixdown can correct many continuity problems with feet and legs.
You can correct transitions and recompute the mixdown as many times
as you like. When the mixdown is satisfactory, you can copy it to
If you want to use the
motion with a different biped, you can copy the mixdown to the current
biped, save the motion as a BIP file, and load the new BIP file
onto the other biped.
The mix can also be saved
as a MIX (.mix) file. A
MIX file can
be loaded onto other bipeds and edited as needed in the Motion Mixer.
Fixing Foot-Based Transitions
with a Mixdown
When you create a transition
between two motions with planted feet (feet with IK constraints),
the motion might not match perfectly between clips. When this occurs,
a planted foot might slide or pop, or a leg might stretch unnaturally
during or near the transition period.
A mixdown can correct
two types of problems during transitions between foot-based motions:
- A foot sliding as it transitions from
one planted motion to another.
- A leg extending completely straight (hyper-extending)
unnaturally to reach a planted position.
The mixdown options on the
Preferences dialog can help correct these
problems. To access this dialog, click Preferences on the Motion
To have an effect on
a mixdown, these options must be set before the mixdown is computed.
If Prompt for options at each Mixdown is turned on, you will be
prompted to set these options each time you compute a mixdown. Otherwise,
the mixdown uses the settings on the Mixer Preferences dialog.
The options in the Mixdown
Options group determine if and how the mixdown affects transitions
between clips with planted feet. Enforce IK Constraints affects
planted feet, while Filter Hyper-Extended Legs affects unnaturally
straight legs. Turn on Prompt for options at each Mixdown if you want
to be asked for these settings each time you do a mixdown. For more information
on these options, see
Mixer Preferences Dialog.
You should not rely
on the mixdown process to correct extreme problems with clips or
transitions. For the best results, adjust transitions before a mixdown
to minimize sliding feet and hyper-extending legs. See
Working with Transitions
To perform a mixdown and copy it to the biped:
- Select the biped in the Motion Mixer
by clicking the biped name at the upper left of the trackgroup set.
- From the Motion Mixer menu, choose Bipeds Compute Mixdown.
If Prompt for options
at each Mixdown is turned on in the Mixer Preferences dialog, you
will be prompted for mixdown options. Click OK to start the mixdown.
A progress bar at the
bottom of the Mixer shows the progress of the mixdown process. After
a few moments, a new track called Mixdown is created as the last
track in the biped’s mix.
You can turn the track
on and off by clicking the track. When the track is solid, the Mixdown
track is on (active), and the biped performs the animation in the
mixdown. When the track appears with hatchmarks, the track is off
(inactive), and the biped performs the animation in the raw mix.
- Click the Mixdown track to make it active.
- Scrub the time slider or play the animation
to check the transitions. If they need correction, turn off the
Mixdown track, correct the transitions, and compute the Mixdown
again. Repeat until the transitions are correct.
- With the Mixdown track active, choose
Bipeds menu Copy Mixdown to Biped.
- Turn off (Mixer
Mode) if it is on.
The mix from the Motion
Mixer is visible on the biped in viewports even though the biped
is no longer in Mixer mode.
- To save the animation as a BIP file,
on the Biped rollout, click (Save
To save Motion Mixer data to a MIX file:
A MIX file saves the
current state of the Motion Mixer data for a selected biped, including
all clips, transitions, trims, scaling and time warps. It is not
necessary to collapse clips before saving a MIX file.
- Select the biped in the Motion Mixer
by clicking the biped name at the upper left of the track set.
- From the Motion Mixer menu, choose Bipeds
menu Save Mix File. Enter a filename for
the .mix file, and click Save.