Background bakes

A background bake runs in a separate Blender, started for you with no window. This Blender stays as light as if nothing were baking, and you can go on working in the same file.

Turn it onCopy Anchor Link

Turn on In Background in Bake Settings, or Bake in Background in the Bake menu: they're the same switch. Now the Bake button (and Continue and Re-bake From) bakes in the background. The progress bar and stop button show as for any bake.

How it worksCopy Anchor Link

1. This Blender saves a copy of the file, as it is at that moment, to its temporary folder.
2. A background Blender opens the copy and bakes it, with the same code as a bake here.
3. When it's done, the particles object here takes the new bake.

While it runs, the object keeps playing its old bake. Changes you make here don't reach the bake; when it finishes, the status says Changed since the bake if you changed something it depends on.

When it's done, the status box shows a line like "Baked 250 frames in the background, 41,207 particles, in 95.3 s", or why it failed.

Things to knowCopy Anchor Link

• Opening another file (or File ▸ New) stops every background bake and throws its frames away. Save, and let them finish first.
• Stop keeps the frames finished, as for a bake here.
• A background bake needs as much memory as one here, on top of this Blender's own.
• With more than one GPU, background bakes spread across them. See Several simulations at once.

RelatedCopy Anchor Link

• Several simulations at once
• The bake controls