# Write USD Overrides


INPUT → The selected Multiverse Compound with MEOW overrides
OUTPUT → USD Override File (.usd/.usdc/.usda)


This shelf button allows to write MEOW overrides for the selected Compound node to a USD file on disk. We call this file a USD “override”.

TIP

Writing overrides is also available through the Multiverse Python API:

multiverse.WriteAsset
1

See the relative API documentation

In Multiverse you set overrides for the items in the node graph tree that each Multiverse Compound encapsulates, whether it represent an assets or a composition.

To set override you use the Multiverse Explore and Override Window (MEOW). This can be done at any point in the hierarchy using the RMB.

When a Multiverse Compound is selected (whether it represent an assets or a composition), the MEOW will display quickly and efficiently a hierarchical tree graph where each row represents a node item in the graph that the Compound encapsulates.

This tree graph matches exactly how it was written, e.g. by the Multiverse Write Asset/Composition or by Solaris USD_ROP.

Overrides to a specific item in the node graph tree are inherited by their children if not explicitly overridden below in the hierarchy, this means you can set an override to a node in the graph and all its children will inherit, minimizing the need to set an override for each node in the tree graph.

Overrides set in MEOW are saved when you save the Maya file, but they can also be written out as .usd files representing a Multiverse USD “override”.

You can choose several option to write your overrides, and use the time settings to output static or animated overrides.

# Input

Select a single Multiverse Compound node (mvUsdCompoundShape).

# File Output

By default, when no extension is typed, this will write a single .usd binary file.

You can also explicitly type the extension:

  • .usd binary file — default in case you don't type an extension.
  • .usdc binary file — exactly the same as .usd: there is no valid reason to specify a .usdc extension, simply use .usd if you want to write binary files.
  • .usda ASCII file — ASCII files should only be used for inspection and for debugging purposes.

TIP

Typically you will read it back in Maya as a layer for the relative Multiverse Compound it overrides. This can be also done automatically if the “auto-sync compound after writing” option is active when writing the override.

# Static / Animated Override

Using the Time Settings you can either write:

  • Static overrides — This is a single USD file, with a single frame containing a single “sample” of data (at the current frame in Maya) which will persist through time.
  • Animated overrides — This is a single USD file, with multiple frames (for a frame range you can specify) each containing either a single “sample” of data per frame, or multiple “samples” of data per frame.

# Reference

Section Parameter Description
Post-Write Actions Auto-sync compounds after writing If this option is on, after writing, in the Multiverse Compound associated to the overrides we will automatically create a layer with the USD override file positioned at the top of the layer stack.
Override Options All Overrides Write all overrides.
Select Overrides Specify the overrides you want to write.
Transforms Write overrides for transformations (Xfrm). These are Maya locator transform nodes and have complete and full support for their ancestors fosterParent nodes associated to items in the node graph.
(Render) Visibility Write override for rendering visibility (RV).
Attribute Sets Write overrides for attributes (Attr). These are Multiverse mvSet nodes associated to items in the node graph.
Material Assignment Write overrides for material assignment (Mat). These are shading group shadingEngine nodes associated to items in the node graph and any "Null Material" assignment (a Null Material removes a pre-written assignment and replaces it with an empty assignment (in such cases material inheritance will then apply).
Variant Selection Write (Var) variant selections that were specified.
Variant Definition Write (Var) variant definitions that were newly created.
Activation State Write override for the activation state (activated/deactivated).
Include Material Namespace Include the "namespace" of materials when writing the override.
Time Settings Current Frame Write a single “sample” of data at the current frame. This produces a static override.
Frame Range Write a single “sample” or multiple “samples” of data for the specified frame range. This produces an animated override.
Start The first frame to write
End The last frame to write
Increment Write every 1 frame or every n-frames according to your n-increment
Sub-frames How many “samples” to write for each frame (they will be equally spaced).
Sub-frames span From the center of the frame, how large is the interval span for each “sample”.
Frames per second Writes the desired frames per second / timecode per second in the header of USD files.
Preview A preview of your time samples.
Last Updated: 6/3/2021, 11:23:49 AM