LocalDispatcher

Schedules execution of task graphs on the local machine. Tasks may be dispatched in the background to keep the UI responsive.

user

Container for user-defined plugs. Nodes should never make their own plugs here, so users are free to do as they wish.

preTasks

Input connections to upstream nodes which must be executed before this node.

postTasks

Input connections to nodes which must be executed after this node, but which don’t need to be executed before downstream nodes.

task

Output connections to downstream nodes which must not be executed until after this node.

dispatcher

Container for custom plugs which dispatchers use to control their behaviour.

dispatcher.batchSize

Maximum number of frames to batch together when dispatching tasks. If the node requires sequence execution batchSize will be ignored.

dispatcher.immediate

Causes this node to be executed immediately upon dispatch, rather than have its execution be scheduled normally by the dispatcher. For instance, when using the LocalDispatcher, the node will be executed immediately in the dispatching process and not in a background process as usual.

When a node is made immediate, all upstream nodes are automatically considered to be immediate too, regardless of their settings.

dispatcher.tractor

Settings that control how tasks are dispatched to Tractor.

dispatcher.tractor.service

A Tractor “service key expression” used to select blades on which tasks will be executed.

dispatcher.tractor.tags

A space separated list of tags that can be used with Tractor’s limits to constrain the number of concurrent tasks. Typically this is used to ensure that tasks using commercial software do not exceed the available license count.

tasks

The tasks to be executed by this dispatcher.

framesMode

Determines the active frame range to be dispatched as follows :

  • CurrentFrame dispatches the current frame only, as specified by the ${frame} context variable.

  • FullRange uses the full frame range as specified by the ${frameRange:start} and ${frameRange:end} context variables.

  • CustomRange uses a user defined range, as specified by the frameRange plug.

frameRange

The frame range to be used when framesMode is “CustomRange”.

jobName

A descriptive name for the job.

jobsDirectory

A directory to store temporary files used by the dispatcher.

executeInBackground

Executes the dispatched tasks in separate processes via a background thread.

ignoreScriptLoadErrors

Ignores errors loading the script when executing in the background. This is not recommended - fix the problem instead.

environmentCommand

Optional system command to modify the environment when launching tasks in the background. Background tasks are launched in a separate process using a gaffer execute ... command, and they inherit the environment from the launching process. When an environment command is specified, tasks are instead launched using environmentCommand gaffer execute ..., and the environment command is responsible for modifying the inherited environment and then launching gaffer execute ....

For example, the following environment command will use the standard /usr/bin/env program to set some custom variables :

/usr/bin/env FOO=BAR TOTO=TATA