When you use different
motions on the upper and lower parts of the biped, you can create
a situation where the balance in the two clips do not match one
another. For example, if the arms are waving wildly in the motion
used for the upper body, the hip motion should compensate to some
degree to keep the biped in balance. A straight mix of this arm
motion with another hip/leg motion will most likely not match up
in terms of balance.
Bipeds with same set
of upper and lower body motions. Biped on the left has balance compensation,
biped on the right does not.
By default, the Mixer
compensates for differences in upper and lower body motion by making
slight alterations to the spine and pelvis motions. If the biped
bends over at the waist, for example, the pelvis will be moved to
compensate for the weight shift, and the spine rotation will be
lessened to help the biped keep its balance. Balance compensation
is intended to make the biped's motion look as natural as possible.
In the Mixer, you can
control the degree of automatic balance compensation using the balance
track. One balance track is automatically created for each biped
as it is added to the Mixer.
If the balance track for
a biped is not displayed, click Preferences on the Motion Mixer
toolbar, and turn on Balance Curves on the
The balance track has
a weight curve for adjusting the degree of automatic balance compensation
between upper and lower body trackgroups. By default, the weight
value of 1.0 across the balance track provides the maximum degree
of compensation. You can reduce the weight curve at various points
to lessen the degree of automatic balancing performed by the Mixer.
NoteEach biped can have
only one balance track, and the balance track cannot be deleted.
For fine adjustments
to balance compensation, you can also change the parameters on the
dialog, available from the Mix menu.
NoteBalance Curves and
related parameters are not available for non-biped mixes.
To adjust balance using the balance track:
- Add a biped to the Mixer, and create
at least two trackgroups for the biped. See
Filtering Mixer Tracks.
- Filter one trackgroup to use motion only
from the spine, arms and head. See
Filtering Mixer Tracks.
This trackgroup will hold the upper body motion.
- Filter a different trackgroup to apply
only to the legs, pelvis and COM tracks. This trackgroup will hold
the lower body motion.
- Add a clip with a great deal of upper
body motion to the upper body track. See
Importing Clips to the Mixer.
- Add a clip with very different lower
body motion to the lower body track.
- Click (Balance
Weight Mode). This button is at the far right of the balance track.
The weight curve becomes
visible at the top of the balance track.
TipIf you can't see the weight curve, click
Preferences to display the Mixer Preferences dialog, and turn on
- Add nodes to the weight curve, and adjust
the nodes. For information on how to add nodes and edit weight curves,
Adjusting Track Weight.
When the weight is set
to 0.0, the Mixer will not adjust the spine and pelvis motion to
compensate for differences in the upper and lower body motion. Values
between 0.0 and 1.0 will adjust the balance to some degree.
To fine-tune balance compensation on
the pelvis and spine:
The values on the Balance
Parameters dialog can be used to make subtle adjustments to the
- In the Motion Mixer, select the biped
by clicking its name at the upper left corner of its trackgroups.
- From the Motion Mixer menu, choose Mix Balance Parameters.
The Balance Parameters
- To adjust the degree of horizontal balance
compensation on the pelvis, change the Lateral Ratio parameter.
Lower values make more forward/backward motion on the pelvis, while
higher values use more side-to-side motion to compensate.
- To adjust the degree to which spine rotation
from the lower body motion is propagated on the upper body, change
the Propagation parameter. Higher values rotate the spine links
to better follow the COM and pelvis motion.
Bipeds with same upper
and lower body motion. Biped on left has Propagation set to 0.0,
biped on right with Propagation at 1.0.