Cache Formats

ZivaVFX uses several cache formats for different scenarios. Following sections introduce each of their usage.

Maya Cached Playback

ZivaVFX v2.0 supports Maya Cached Playback feature since Maya 2022. This feature allows users to preview the simulation result. The simulation runs in the background and caches the deformed meshes in the memory while the user can still operate and edit scenes in the foreground. When the caching finishes, the user can scrub the time slider back and forth to preview the result at will. The caching process will re-run from the nearest keyframe when attribute changes, which includes triggering re-run when unrelated attributes are updated. (e.g., changing ‘Show Bones’ attribute can trigger unnecessary re-sim.)

Note

The Attachment Damping (check Damping under Physical Effects) does not work correctly when Maya cached playback triggers resuming simulation from middle of time range. Make sure to run it from the start frame if Attachment Damping is turned on.

This cache is stored in memory only and can not be serialized. Note that this feature simulates the scene with the same speed and resource usage. That means if your scene is heavy and complex, background simulation will consume significant CPU and memory resources. ZivaVFX will be less responsive during foreground operations. So for such a scenario, turn off the Cached Playback before opening the scene.

Ziva Simulation Cache(zCache)

The Ziva Simulation Cache is a file format that stores the solver’s output.
When the zCache node is added, the solver’s output will be saved in the memory once the simulation starts. Each subsequent time you run the simulation, it will be played back from the cache instead of re-solved. If you reach the un-cached frames, the solver will begin simulating again, and the results appended to the cache. Once the cache is created, anytime you wish to re-generate the simulation result you will need to first clear the cache.
The Ziva Simulation Cache can be serialized to file. After deserializing the cache file, the solver can quickly go through cached frames and resume the simulation from the first uncached step. The application of Ziva Simulation Cache is to improve the playback speed, and to skip those verified frames and focus on tuning the problematic frames.
For the menu item introduction, refer to Simulation RAM Cache.
For MEL command reference, refer to ziva and zCache commands.
For node reference, refer to zCache and zCacheTransform pages.

Alembic Cache

The Alembic is the default file cache format to export the ZivaVFX simulation result. It is a standard file format to exchange data between applications and departments.
To export the SoftBody meshes, use following Maya menus:
Cache → Alembic Cache → Export All to Alembic…
Cache → Alembic Cache → Export Selection to Alembic…

Comparison between Cache Formats

Cache Format	Storage Type	Serializable	Playback speed	Support Maya Version
Maya Cached Playback	Memory	No	*****	Since 2022
Ziva Cache	Memory/File	Yes	**	All Maya Version
Alembic	File	Yes	**	All Maya Version