Sometimes you want a job to be sent only to some workers, but not all of them. This can be due to memory requirements of that job, the GPU the workers have available, or any other reason. This is what you can use tags for.
How this works is easiest to explain when we look at two perspectives:
- A job can have one tag, or no tag.
- A job with a tag will only be assigned to workers with that tag.
- A job without tag will be assigned to any worker.
- A worker can have any number of tags.
- A worker with one or more tags will work only on jobs with one those tags, and on tagless jobs.
- A worker without tags will only work on tagless jobs.
Blender Studio have two groups of Workers:
- Artist machines, with powerful GPUs. These are suitable for EEVEE renders, but also Cycles-on-GPU, and can also help with Cycles-on-CPU jobs.
- Render servers, with lots of CPU power, but no GPUs. These can only do Cycles-on-CPU jobs.
To support these different cases, they use three tags:
The artist machines get all three tags. The render servers just get the
Cycles tag. When submitting a job, the artists will chose the tag that is
suitable for that particular job.
Choosing the tag for a job is something you have to do yourself. In this example case, the tag could in theory be picked automatically depending on the active render engine. The tagging system is more general than that, though, and so Flamenco doesn’t know what you want to use the tags for.
For more info on GPU rendering with Flamenco, see FAQ: How do I make the Workers render on GPU?