`file_cache`

An experimental node which can cache and read back simulations by writing them to a file.

Note:

This is an experimental node that might change in the future. Compounds and graphs that use it might not work properly with later versions of Bifrost.

This node is intended to be in a graph upstream (to the right of) a simulation. It can cache the simulation to disk or read the cache of the simulation from disk. Lazy mode can dynamically switch from "read" to "write" based on whether the files exist on disk.

It can write .bob (Bifrost Object) filaes, Alembic, or OpenVDB files. File types are controlled by the extension on the filename parameter - files ending in ".abc" are written as Alembic, ".vdb" as OpenVDB, and ".bob" (or anything other extension) are written and read as Bifrost object files.

Usage

Set a file path for the cache of your simulation in filename. It may contain environment variables, such as $HOME for your home directory.
Plug the output of a simulation into objects and use out_objects as the output.
Go to the start frame of the simulation.
Set mode to lazy mode.

`Mode`

Lazy mode switches between read and write mode depending on whether or not a frame exists on disk. This mode can be used as a scrubbable, resumable cache.
Write mode pull upstream and writes frames and passes geometry through.
Read mode does not pull upstream and reads frames, outputting the geometry.
Passthrough mode always pulls upstream, does not write anything, and passes geometry through.

Alembic and OpenVDB settings

For more detail on these, see the documentation on write_Alembic and write_OpenVDB. These nodes are used internally. File cache shares the same features and limitations of these nodes.

Frame Range

If active_frame_range is enabled, then the node defaults to passthrough behavior outside of the specified frame range. If inverted is enabled, then it switches to passthrough behavior inside the specified frame range.