Each track has one or
weight curves that
you can use to mix motion from several tracks to varying degrees.
The weight curve determines how much a specific track contributes
to the motion within the trackgroup.
With weight curves, you
can create several full or partial transitions between all the tracks
in a trackgroup. Compare with transitions on a
which can only create a full transition between two clips.
Weight curves are useful
- Creating transitions between two tracks
in a trackgroup.
- Creating random motion.
- Experimenting with transitions quickly
Each track's weight curve
appears as a thin black line across the top of the track.
If you can't see
the weight curve, click Preferences to display the
. Turn Weight Curves
off and on and watch the display to see the weight curve appear.
You access the weight curve
by clicking the Weight Mode button at the right end of the track.
Clicking Weight Mode on the Motion Mixer toolbar enables weight
curve editing for all tracks. When Weight mode is on, you can work
only with the weight curve, and not with clips.
You edit a weight curve
using nodes (points) on the curve. Clips on layer tracks automatically
have a node at each end of each clip. A transition track has no
nodes by default.
Weight Curve Evaluation
By default, each track's
weight curve is set to a value of 1.0 across the entire track, which
uses 100% of the track's motion in the mix. When you change the
curve to dip to a value below 1.0, the motion on the track is mixed
with the motion on the track below it. For example, if you set the weight
curve for two tracks in a trackgroup to 0.5, the two clips will
be mixed equally.
Several tracks can be
stacked in a trackgroup with varying weight curves on each one.
For each frame in the animation, the Motion Mixer evaluates the
curve on the topmost track. If its weight curve is less than 1.0
at that frame, the Mixer evaluates the next track down, and so forth.
The Motion Mixer adds up the weight curve values until the sum reaches
1.0, and disregards tracks below that point.
For Transition tracks,
one weight curve is used for the entire track. On Layer tracks,
weight curves are set individually for each clip.
To adjust a weight curve:
- Open the Mixer, add a biped to the Mixer,
and create two tracks for a trackgroup. See
Filtering Mixer Tracks.
- Place different motion clips on the tracks.
- For the topmost track in the trackgroup,
click (Weight Mode). This button
is to the right of the track display.
The weight curve turns
red to indicate it can be edited.
You have to do the next
two steps only if the weight curve has no nodes, or would like to
create more nodes.
- Move the cursor over the line until a
small arrow appears. Click to set a node.
- Move the cursor and click to set more
nodes on the weight curve.
TipOn a transition track, you would ordinarily
set a node at each end of the track, and at intervals in between.
The number of nodes you set depends on the type of curve you want
to make. Make as few nodes as possible to get the curve required
for your animation.
- Move the cursor over an existing node
until a cross cursor appears.
- Click and drag to move the selected node
The Motion Mixer mixes
the motions from the topmost track with the track below it on that
frame. The motions are mixed to a greater or lesser degree depending
on how low you set the weight curve value for the topmost track.