Apple Shake 4 - Manual (Page 349)

Chapter 13 Image Caching 349
Commands to Clear the Cache
Ordinarily, cached frames in memory are written to disk and cleared as appropriate
whenever you quit Shake. If necessary, you can also choose to clear parts of the cache
manually while Shake is running.
Important: It’s advisable to quit Shake normally whenever possible. If Shake quits
unexpectedly, or you force-quit Shake yourself, the disk cache is invalidated. As a result,
the remaining data on disk is unusable by Shake. Upon startup, you are prompted to
either move the current cache to a temporary location, or disable caching.
Two commands in the File menu in Mac OS X are available to clear the cache:
Flush Cache
When you choose Flush Cache, all appropriate images are copied from the memory
cache to the disk cache (depending on how the cacheMode parameter is set), but the
memory cache is not cleared. This command is similar to what Shake does when you
quit (the delay that occurs when you quit is Shake flushing the memory cache to disk).
Purge Memory Cache
Similar to the Flush Cache command, but the memory cache is cleared afterwards. This
is useful if most of your RAM is filled with cache data, and you want to free it up to
create and play a flipbook without needing to exit Shake in order to clear the memory
cache.
Memory and the Cache in Detail
Shake incorporates two separate caches: an image cache and a processing cache.
The image cache is used to store output images that nodes produce. By storing the
entire output image, the image cache can effectively “bake” portions of the processing
tree, thereby saving re-computation time. Whether or not a node’s image data is sent
to the image cache primarily depends on the node’s position in the node tree. When
editing, the nodes directly above the node that is currently being viewed have the
highest priority, which increases user interactivity. During playback, the node currently
being viewed has the highest priority. The global plugs used to control the image
cache are as follows:
• diskCache.cacheSize
• diskCache.cacheMemory
• diskCache.cacheMemoryLimit (Shake v3.5 and later)
• diskCache.cacheMaxFile
• diskCache.cacheMaxFileSize