Render farm
The render farm is a key piece of the pipeline. It allows artists to render their images using various render engines like V-Ray, Redshift or Arnold.
After an artist has conformed/published all the necessary files linked to a scene and the scene itself, he can submit a job to the render farm.
Concepts
Job
A Job is the top level workload on a render farm, it is described with a name, a priority and most of the time the specification of computers to run on.
Task
Usually a job is composed of tasks which are smaller units of work to be done. For example one computer might render the frames from 1-10 and another one from 11-20.
Command
A task then has commands which are sent to the computer through a Shell (for example bash in case of Linux or cmd.exe for Windows) or directly interpreted by the computer.
For example:
rez env vray test_pipe -- vray
-skipExistingFrames=1
-display=0
-progressUseColor=0
-progressUseCR=0
-progressIncrement=5
-verboseLevel=3
-rtEngine=0
-sceneFile=scene.vrscene
-imgFile=out_frame.exr
-frames=1;2;3;4;5;6;7;8;9;10
tip
The above command uses Rez which is used to resolve environments dynamically by defining packages and environment variables. It's very useful in a render farm setup since we have various software packages and different versions.
Blade
A blade is a computer working on the render farm. It receives a task from the master engine and executes commands.
The blade store and sends logs and status update to the engine.
Engine
The engine is the program running on the main server on the network. Its job is to receive job orders dispatch tasks to the connected blades. It handles priority, logs and a database where it stores information about what is happenning.