8

Motion Flow Mode 895
example. For a crowd, you must share one motion
flow script among many bipeds.
If you are driving a crowd using delegates and
behaviors, then rather than a completely random
motion, the software picks appropriate clips based
on the delegate’s speed and direction. If the
delegate slows to a stop, the s of tware w i ll find and
use a clip that slows to a stop, if one exists.
In all crowd simulations you must load clips
and create transitions before synthesizing the
crowd motion. Often, many clips are used to
sy nthesize crowds. Automatic tr ansit ions relieve
you of having to create transitions between clips
manually.
One additional rollout displays in Motion Flow
mode:
•
Motion Flow (p age 2–897) :DisplaytheMotion
Flow Graph; load and save motion flow files
(
.mfe) . The Motion Flow rollout also contains
a Scripts section where you can create scr ipts,
edit transitions, create a unified motion, and
create random motions for the bipeds.
Note: In Motion Flow mode, some characte r
studio controls are disabled.
Workf low: G etting Star ted with Clips
and Transitions in M otion Flow Mode
Create your own library of .bip files from
imported, and converted, motion capture data,
and from your own char ac ter animation. With
a biped selected, turn on Motion Flow mode.
Select Show Graph on the M otion Flow rollout
to open the M otion Flow Graph. On the M otion
Flow Graph, click Create Clip, and add clips in the
Motion Flow dialog. Associate the clips to
.bip
files by first turning on Select Clips-Transitions
on the Motion Flow Graph toolbar and then
rig ht-clicking a clip icon; a clip dialog appears,
allowing you to browse for a clip.
Click Define Script on the Motion Flow rollout,
then select a series of clips on the Motion Flow
Graph. By left-clicking on a clip it will appear in
the Scripts list. The clips are connected visually in
the Motion Flow Graph with red arrows (active
script) representing default transitions (Minimum
Motion Loss). The default duration for a tr ansition
is 25 frames, which provides good results in
many cases. Transitions, by default, use velocity
interpolation between clips.
Use Edit Transition in the Scripts section to
fine-tune the transitions between clips. Select
a clip in the Scripts list, then from the Scripts
commands, click Edit Transition; the
Transit ion
Editor (page 2–902)
displays,andthesourceand
destination clip names are displayed at the top of
the Transition Editor.
In the Source Clip area, Start Frame represents
theframeinthesourcefilewherethetransition
starts. For example, if Source Clip Start Frame
is 60, the transition
from thesourceclipstartsat
frame 60. The
duration of the transition is set in
the Length field at the upper left; Length values
are in frames. In this example, if Length is set to
10, the transition to the destination clip takes 10
frames. In the Destination Clip area, Start Frame
represents the fr a me in the
destination clip that
the transition starts; a value of 80, for example,
starts the transition at frame 80 of the
destination
clip. In this example, the source clip plays from 0
to 60, there is a 10 frame transition from f r ame 60
of the source clip to frame 90 of the destination
clip(frames80to90coverthedestinationclip
transition period), then the rest of the destination
clip plays.
When the Transition Editor displays, the first
things to try, before m anually editing the
transition, are the Optimized Transitions.
Optimized t ransitions use a minimum foot sliding
algorithm. The top right-hand corner of the
Transition Editor dialog is the icon for optimized