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760 Chapter 8: Modifiers
New—
Creates a new, empty cache file. After setting
a new file, use Record to create the cache data.
Loa d—Loads a vertex animation f rom a cache
file on disk into the Point Cache modifier. If the
number of vertices in the cache file does not match
the number of vertices in the object, a warning
appears, but no error occurs.
Unload—Temporarily f rees the c urrent cache file,
so it can be edited or deleted externally.
Reload—Reopens the current cache file, if
previously unloaded.
Cache Info group
Displays cache statist ics in read-only format,
including the point count, sample rate, sample
count, start/end frames, and er rors, if any.
Record group
Cont ains settings for recording cached animation.
Start Frame—Sets the first frame for recording the
vertex animation. Default=first frame of the active
time segment.
Using decimal fr actions lets you start at a
sub-frame setting when using a Frame:Ticks time
display. Default=0.0.
End Frame—Sets the last frame for recording the
vertex animation. Default=last frame of the active
time segment.
Using decimal fr actions lets you start at a
sub-frame setting when using a Frame:Ticks time
display. Default=0.0.
Sample R ate—Sets the number of frames between
each recorded sample. When rendering with
motion blur, which uses sub-frame sampling,
decrease this value. Default=1.0.
At the default value of 1.0, Point Cache records
one sample p er fr ame. Increasing the value causes
asampletoberecordedeveryNthframe. For
example, a va lue of 10.0 records every tenth frame.
Decreasing the va lue causes multiple samples to
be recorded for each frame. For example, if you
setSampleRateto0.1,PointCacherecords10
samples per frame at evenly spaced intervals.
Record—Stores the vertex animation to a disk
file. If no cache file is specified, or the specified
filedoesn’texist,activatestheSavePointsdialog,
which lets you specify a path and file name for
the cache file. Click Sa ve to record the file, and
then load it into the Point Cache modifier, ready
for playback.
Tip: Tochangethepathorfilename,useCacheFile
group>Newandspecifyadifferentcachefile.
Ena ble M odif ier s B elow—Tur ns on all stack
modifiersbelowthePointCachemodifier.Usethis
when you want to change m odifier settings.
Disable Modifiers B elow—Turns of f all t he object’s
stack modifiers below Point Cache so that only the
cached vertex animation appears when you play
back the animation.
Load Type group
Local —The method t he modi fier uses to load the
cache file. The options are:
•
Stream—Keepsthecachefileopenforfast
access,butloadsonlyasingleframeatatimeto
conserve memory. This is the default mode.
•
Per-S a mple—Opens the cache file, reads a single
frame, and then immediately closes the file.
This is slower than the Stream method, but is
useful if many users are reading/wr iting the
same set of cache files since the cache files won’t
be locked open as you read from them.
•
Pre-Load—Loads the entire cache file into
memory for fast access, and then closes the
file. This is particularly useful in networked
situations, or when a few cache files a re used by
many objects in one scene. In the latter c ase,