The cache folder
Where bakes are written, what each file is, how big they get, and how to take a project to another computer.
Every bake is written to disk, one file a frame, in the cache folder. By
default that's a folder named vecflow_cache beside the .blend file.
Where it is
Folder in Bake Settings sets it. // means the .blend file's
folder, so the default //vecflow_cache moves with the project. An unsaved
file bakes into Blender's temporary folder: save first to keep your bakes.
Inside it, bakes are kept by file, object and bake:
vecflow_cache/
my_shot/ one folder for each .blend file
Water/ one for each simulation
bake_0003/ the bake it plays
frame_0001.ply
surface_0001.ply
state_0010.bin
…Each .blend has its own folder, so two files sharing a cache folder (or a copy made with Save As) never remove each other's bakes. Each bake goes in a new numbered folder; when it finishes, the object plays it and the old one is removed, unless another object still plays it. A duplicated object plays its original's bake until it bakes its own.
The files
| File | Holds | Opens in |
|---|---|---|
frame_0001.ply | The particles at that frame: where each is, its velocity, spin, size and colour, and the values the flow exports | Any program that reads PLY |
surface_0001.ply | A liquid's surface mesh at that frame, with each vertex's velocity | Any program that reads PLY |
smoke_0001.vdb | The gas at that frame: smoke, heat, fuel, flame and velocity | Any program that reads OpenVDB |
mesh0_0001.ply, meshes.json | Cloth and ropes: where each vertex of the mesh is, and what's torn | Any program that reads PLY |
state_0010.bin | A state save, to carry on from | VecFlow only |
flow.json, values.json, run.json, log.txt | What was baked, the values' ranges, where it ran, and the bake's log | A text editor |
The smoke files are written with Blender's own OpenVDB module and play without VecFlow.
How big
A bake grows with its particles and its frames: a frame file holds a row for each particle. Smoke files keep only the cells with something in them, at half precision, so a plume costs what it fills. A state save is about a frame's worth; with smoke, several frames' worth.
Free space you don't need with Free Bake in the Bake menu (it deletes that simulation's bake). Bakes of files you've deleted stay in the cache folder until you delete their folders yourself.
Moving a project
The particles object finds its bake by a path relative to the .blend
(//vecflow_cache/...). Move or copy the whole project folder, cache and all,
and it plays its bakes. A cache folder set to an absolute path stays where it
is.
Collect for Render
Bake SettingsCollect for Render asks for a folder and saves a copy of the .blend there, with the bakes it plays beside it. The folder renders on another computer, even one without VecFlow: the playback reads plain PLY and OpenVDB files. State saves are left out, and the open file is left as it was. It waits until no background bake is running.