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758 Chapter 8: Modifiers
object takes up only a portion of the path, so the
effect can be subtle.
Path Deform Axis group
X/Y /Z—Chooseonetorotatethegizmopathto
align with a specified local axis of the object.
Flip—Reverses the g izmo path 180 degrees about
the spe cified axis.
Point Ca che M odif ier
Select an object. > Modify panel > Modifier List >
Object–Space Modifiers > Point Cache
Select an object. > Modifiers menu > Cache Tools > Point
Cache
The Point Cache modifier lets you store modifier
andsub-objectanimationtoadiskfilethatrecords
only changes in vertex positions, and then play
back the animation using the information in t he
disk file instead of the modifier keyframes. This is
useful when the computation required for vertex
animation b ecomes so excessive that it causes
animation playback to run slowly or drop frames.
Anotheruseforthismodifieristoapplythesame
animation to a number of objects, varying the
Start Time and Strength settings for each so they
don’t all move identically.
The Point Cache modifier is also available in a
world-space version, for which usage is the same.
Sp eci a l Featur es i n P oint Cache
Both versions of the Point Cache modifier provide
enhanced animation capabilities, including:
• Adjustable playback ranges and a playback
graph, to animate w hich cache frame is played
back. This lets you load a cache and then
animate it, slowing down, stopping, reversing,
etc.
•Nth-framesampling,soyoucansampleevery
few frames to save disk space if sampling
every frame is unnecessar y, or record multiple
samples per frame for improved motion
blurring.
•The"strength"isadjustableinAbsolutemode,
so you can easily blend the cache with what is
below in the stack.
•Improvedcachefilemanagement.
• Pre-loaded caches to speed up playback.
Procedure
To use the Point Cache modifier:
1.
Use one or more mo difiers to animate an
object. For example, you might apply a Bend
modifier (page 1–560), and then set keyframes
for the Angle parameter to make the object
bend back and forth.
2. Click Play Animation.
If the animation is a good candidate for caching,
the playback w ill drop m any frames with Real
Time Playback turned on, and w ill run slowly
w ith Real Time Playback tur ned off.
3. From the Modif y panel > Modifier List,
choose Object-Space Modifiers > Point Cache.
4. On the Parameters rollout > Record group, set
frame numbers for Start Time and End Time.
5. If you plan to render the cached animation
usingmotionblur,decreasetheSampleRate
setting.
6. Click the Record button, and use the Save
Cache dialog to specify a cache file.
The software records the animation to the
cachefile.Whenfinished,thecachefilename
appears in the Cache File group.
7. IntheRecordgroup,clickDisableModifiers
Below.