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Sublayering overlays the contents of the imported file over the existing contents. Each tree’s “opinions” about prims with the same path, and (on those prims) properties/metadata with the same name, are merged based on opinion strength (see below).
This is useful when combining files that are each meant to contribute a portion of a complete scene. For example, composing separate layers representing set layout, props, characters, effects,and lights.
An inherent feature of sublayering is that “everything stays in the same place”. Prims have the same path in the new file as they had in their source file.
Because each of these departments is working in a separate sublayer, they don’t need to worry about sharing a single file and having conflicting edits. But because they are all working in the same scene graph hierarchy, each department can apply changes to any of the content created by other departments.
The Sublayer LOP loads new sublayers into the scene. LOP networks in general are always editing the strongest sublayer of an empty root layer. Some LOP nodes may start a new, stronger sublayer which is then modified by all following LOP nodes. These network output is the composition of this sublayer stack.
Top-level file that specifies sublayers
#usda 1.0 ( subLayers = [ @shotLighting.usd@, @shotFX.usd@, @shotAnimation.usd@, @shotSetDressing.usd@, @sequence.usd@ ] )
The “target” layer you want to add to the layer stack is often in an external file, however this node can also import the layer(s) in the output of another LOP node.
Sublayer in an external file
Sublayer in a layer the output of a LOP node
You can use the table below the parameters in the parameter editor to re-order the connections to the multi-input.
Remove an existing sublayer file from the stack
This only works for layers with Save Path metadata (that is, layers loaded from disk, or layers you've explicitly set Save Path metadata on with the Configure Layer LOP).
You can use the Scene graph layers pane to view the results of adding the sublayers.
The stage to which this node will add new sublayers.
Second Input (multi-input)
When Sublayer Type is “Sublayer Inputs”, the node adds layers from stages connected to this multi-input into the layer stack in the first input.
When this option is on (the default), the payload loading configuration of the input stage is not changed. When this option is off, the stage’s load mask will be modified to turn off all payload loading. Note that this will affect the loading of payloads anywhere in the stage, not just payloads loaded by the sublayers added by this node. Use the Configure Stage LOP to have more control over which payloads are loaded on the stage.
Copy Layer Metadata to Stage Root Layer
Layer metadata is not composed by USD following the normal rules. In order for values like the frames per second or up axis settings to apply to a USD stage, they must be set directly on the root layer of the stage. This means any layer metadata authored on a file being loaded by this node will not affect the stage level metadata. This options allow for the explicit copying of layer metadata from the first layer loaded by this node on to the stage’s root layer. If multiple files are specified, it it always the first file that has its values copied to the root layer.
Auto option for this parameter acts like a
Yes (copy the sublayer’s metadata to the root layer) if there is no input connected to the first input of this node. Otherwise it behaves as a
No (does not affect the stage’s root layer metadata).
Edit Root Layer
When this is on (the default), the new sublayers are added to the layer stack. This is usually what you want. When this is off, the content of the imported layers become sublayers of the active layer.
Turning this on or off usually does not make a visible difference, but affects the priority given to opinions on the layers, and what content is in what layers when you write USD to disk.
A space-separated list of patterns that match layers by their “source file” metadata. This selects the layers for removal or reordering when you use the Remove found sublayers or Sublayer position parameters below.
Remove Found Sublayers
Turn this on to remove any layers that match the patterns the Find sublayers.
This is useful if you want to replace layers rather than just add them. For example, you may be editing a layer that has sublayers for animation, effects, and lighting. If your LOP network generates a new version of the effects layer, you would want to remove the existing effects layer and replace it with the new one.
Where to add sublayers from.
Import layers from file(s) on disk.
Import layers from LOP node branches connected to this node’s multi-input.
Handle Missing Files
When Sublayer type is “Sublayer files”, what to do when a file (either a file you specify or a file referenced inside another file) cannot be found.
Error for Missing Files: The node errors, preventing cooking the rest of the network.
Warn for Missing Files
The node shows a warning, then passes through the first input unchanged.
Ignore Missing Files
The node silently ignores the missing file, and passes through the first input unchanged.
Allow Missing Files on the Stage
Author the reference to the sublayer even if it currently doesn’t exist. This node and the following nodes will probably print warnings from the USD libraries about missing files.
Where in the sublayer stack to insert the new layers. The position affects the priority of its opinions compared to other layers.
Add the new layers as the strongest sublayers. The opinions in these layers override all other layers.
Add the new layers as the weakest sublayers. The opinions in these layers will be overridden by any sublayer with an opinion on the same data.
Strongest File Layer’s Position
Add the new layers where their opinions are stronger than the strongest layer that is loaded from a file on disk. This option can be used to keep all LOP-authored layers together, allowing them to be flattened into a single layer when saving to disk.
Strongest Found Layer’s Position
Add the new layers where their opinions are stronger than the strongest layer found by the Find Layers parameter.
Weakest Found Layer’s Position
Add the new layers where their opinions are weaker than the weakest layer found by the Find Layers parameter.
Insert the new layers into the sublayer stack at a specific position (set by the Position index parameter below). Lower numbers represent stronger opinions. Setting this to
0 is the same as choosing “Strongest Position”.
When Sublayer position is “Specific index”. Insert the new layers at this specific position. Lower numbers represent stronger opinions. Setting this to
0 is the same as setting Sublayer position to “Strongest Position”.
Number of Files
This node can sublayer in more than one file at a time. Enter the number of files to import, or click the plus and minus buttons to add or remove layer files.
Whether to load this file.
The file path to the file.
Time Offset (in Frames)
Offsets all time samples from the file. You can use this to re-time animations in the references file.
Scales all time samples from the file. You can use this to re-time animations in the references file.
Load the layer but immediately mute it. This may be useful if the layer must be loaded for other layers to work, but you don’t need to edit or display it.
Click to reload the contents of all files imported by this node.