Cache and budgets
The Cache box in the add-on preferences controls where baked frames go and how much space they may use.
How the cache is organised
Section titled “How the cache is organised”Baked frames go to a per-session folder inside the cache directory. The cache directory is the system temp folder unless you set one. Two Blender instances therefore never overwrite each other’s frames, and stale sessions are cleaned up automatically. When you save the .blend file, the cache moves next to the file’s own cache.
Both RAM and disk use are capped. When a cap is reached, the least recently used frames are evicted first.
Settings
Section titled “Settings”| Setting | Default | What it does |
|---|---|---|
| Directory | empty (system temp folder) | Parent folder for baked frames. A per-session subfolder is created inside it. |
| Disk Budget (GB) | 8.0 | Maximum size of the frame cache on disk. 0 disables the cap. At a million particles a frame is about 32 MB, so a long bake can fill a drive if you disable it. |
| Memory Budget (GB) | 0 (automatic) | Maximum RAM used by the in-memory frame cache. 0 means 25% of physical RAM, or 4 GB if that cannot be determined. |
| Surface Budget (GB) | 20.0 | Disk space for liquid surface meshes made with older mesher settings. 0 disables the cap. |
| Live Gas Preview | off | Writes every frame of a live Blaze run to disk as OpenVDB so it can be scrubbed and rendered later. Off, a live run only streams the viewport preview, which is several times cheaper. Use Bake to cache. |
Changing the directory
Section titled “Changing the directory”A change to Directory applies to the next bake or run. Click Apply Now to switch immediately. BLUX asks you to confirm, because frames already cached stay in the old folder and are no longer shown. Apply Now is refused while a simulation is running.
If the folder you enter is not usable, a red message explains why and shows which folder is still in use.
Surface budget
Section titled “Surface budget”Liquid surfaces have their own budget so they never evict simulation frames. To stay under it, only surfaces made from older settings are deleted. The surface sequence on screen and the one being meshed are never deleted.
Blaze checkpoints
Section titled “Blaze checkpoints”Blaze bakes write checkpoints (checkpoint_<frame>.npz) into the same folder. A full 128³ dense grid is about 120 MB per checkpoint. They count toward the disk budget and are removed with the cache.
Status lines
Section titled “Status lines”Under the settings, the page shows the active cache folder and the range of cached frames, or says that no cache exists yet (it is created at the first run). Use Refresh Status to update it.
Surface mesher status
Section titled “Surface mesher status”The last row of the Cache box reports whether the Production liquid mesher (pysplashsurf) is installed in the solver’s Python, with an Install button when it is not. Without it, BLUX uses the Geometry Nodes mesher. See Dependencies.