'Quit after current frame' option for command line renders
Would be great to have an option to halt animation renders at the finish of the current frame. This would be good for when you need to shut down a render node, but without losing already partially rendered frames. In particular this would be useful when there are multiple instances rendering a scene. Killing one of the renderers can leave a gap in the output sequence, if the other machines have already moved on to later frames. Currently ctrl-c halts the renderer and ctrl-c ctrl-c kills it instantly, I'm not sure what chord would be appropriate, maybe ctrl-f for stop after the current Frame?
8 Comments
This is one of those situations that calls for "use an addon/solution tailored to batch rendering."
Exactly. When doing renders both Blenders native UI as well as the terminal aren't very suitable for real work. The native UI is made for a single render and the terminal is missing an interface. Better IMO, like others here write, to use a dedicated render manager which has a cue. B-renderon, which is such software, has exactly this feature already: 'Stop after current frame is saved' (BTW it also has 'Stop after current job(s)' (as it can handle multiple render jobs of multiple blend files etc.) and ' Stop selected blend's render'
Millions of terminal users would argue with your description of it "missing an interface". It has an interface, just one you type into, rather than click with a mouse.
No one except terminal users describes a terminal as an "interface", in the context that the rest of the world speaks of one.
At that point, why not use an actual render manager like Flamenco ? It's made by the Blender Fundation, and AFAIK it's what they use in production at the Blender Studio. And I use it personally, even when rendering on a single machine, because it makes managing render jobs just that simpler.
CTRL-C does exactly what you describe. It will exit after the current frame has finished and saved. The double CTRL-C exits immediately without finishing the current frame. This can be tested by sending signals to the process.
No, ctrl-c will kill the process gracefully, but not always after the current frame.
I see blender.stackexchange.com/questions/6781/abort-script-that-renders-frames mentions a solution. But yeah it requires some scripting.
CTRL-C is something that your OS translate to a signal (SIGINT) and sends to the application. The application can response to this. Adding a different key-stroke like CTRL-F is something that needs to be configured in your OS and use one of the existing signals. Currently a SIGINT does something similar as pressing the escape key and you're right that doesn't finish the render. (ref projects.blender.org/blender/blender/src/branch/main/source/creator/creator_signals.cc )
Best solution is to configure what should be done in case Blender receives the first CTRL-C (exit after sample or exit after frame) so we keep the same behavior where render farm managers rely on. Something like
--sigint=exit-after-frame/exit-after-sample.