USDLayerWriter
Takes two input scenes and writes a minimal USD file containing the differences between them. This new file can then be layered in a USD composition to transform the first scene into the second. This is useful for baking modifications made in Gaffer into a USD file for consumption in other hosts.
A typical use case might be to share lookdev authored in Gaffer, with a workflow like the following :
A SceneReader brings
model.usd
into Gaffer.Shaders and attributes are applied in Gaffer, using Gaffer’s standard scene processing nodes.
A USDLayerWriter is used to bake this lookdev into a new
look.usd
layer on disk, with the SceneReader formodel.usd
connected to thebase
input and the lookdev connected into thelayer
input.A new USD file is created that layers
look.usd
overmodel.usd
. This is loaded into Gaffer or another host for lighting.
Note
To write a complete USD file (rather than a layer containing differences) use the standard SceneWriter node.
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.
base
The base scene that the layer
input is compared to.
layer
The scene to be written to fileName
. This is compared to the
base
scene, and only differences are written to the file.
fileName
The name of the USD file to be written.
Supported file extensions : usd, usda, usdc
out
A direct pass-through of the layer
input.