The Component Creator allows you to create a USD asset from Maya scene objects or USD prims. The resulting USD hierarchy is structured according to a customizable JSON template, making it ideal for standardizing your structure between assets.

Component Creator Options

To understand how your components will be structured, or to set a custom template file, open the Component Creator options dialog by clicking the options box at the Create Component menu.

Output

Template Specifies the JSON template used to structure the resulting USD asset (ASWF standard by default). You can click Open Template Location to quickly navigate to the template file's location on disk.

ASWF standard example:

    "at_origin": false,
    "center_component": false,
    "class_prefix_path": "",
    "component_prim_path_pattern": "/root",
    "file_extension": "usda",
    "filename_pattern": "{component_folder}/{component_name}/{component_filename}.{file_extension}",
    "flatten_source": false,
    "materials_scope_name": "mtl",
    "meshes_scope_name": "geo",
    "options_description": "ASWF Standard options for the component creator.\nIt represents the component structure that we want to\npromote as the correct way to encapsulate a component.",
    "options_name": "ASWF Standard (default)",
    "payload_filename_pattern": "{component_folder}/{component_name}/{scope_name}/{variant_selections}.usdc",
    "scope_layer_filename_pattern": "{component_folder}/{component_name}/{scope_name}/{scope_name}.{file_extension}",
    "sub_layers_in_payload": true,
    "sub_layers_payload_filename_pattern": "{component_folder}/{component_name}/payload.{file_extension}",
    "variant_name_pattern": "{object_name}",
    "variant_numbered_pattern": "variant_<n>",
    "variant_set_name_pattern": "{object_name}",
    "variant_set_numbered_pattern": "variant_set_<n>"

Option	Type	Description
options_name	Text	Name of the options template
options_description	Text	Description of each option used in the Component Creator.
flatten_source	Boolean	Control if the source USD file is to be flattened into a single layer. Default: false
file_extension	Text	The USD file extension to use: 'usd', 'usda', or 'usdc'. Default: usda
center_component	Boolean	Optionally center the component bounding-box at the origin. Default: false
at_origin	Boolean	Optionally clears the transforms of root transformable prims. Default: false
class_prefix_path	Sdf.Path	The path prefix to be used to generate the class names of the components.
sub_layers_in_payload	Boolean	Control if sub-layers are put in a payload or directly in the root layer. Would put the same sub-layers in multiple places. Default: true
meshes_scope_name	Text	Name of the mesh scope. Default: "geo"
materials_scope_name	Text	Name of the material scope. Default: "mtl"
component_prim_path_pattern	Text	The component path pattern to be used to generate the component path.
filename_pattern	Text	The filename pattern used to generate the file name of the component.
sub_layers_payload_filename_pattern	Text	The filename pattern used to generate the sub-layers payload.
scope_layer_filename_pattern	Text	The filename pattern used to generate the filename of the scope sub-layers.
payload_filename_pattern	Text	The filename pattern used to generate the filename of the payloads.
variant_set_name_pattern	Text	The name pattern used to generate variant-set names.
variant_set_numbered_pattern	Text	The name pattern used to generate numbered variant-set names.
variant_name_pattern	Text	The name pattern used to generate variant names.
variant_numbered_pattern	Text	The name pattern used to generate numbered variant names.

Prim Hierarchy Preview

Displays a generalized version of the prim hierarchy according to the template.

File Structure Preview

Displays a generalized version of the USD file structure on disk according to the template.

For more information on the remaining options, see USD Export Options

For a more complete, in-depth description of templates, see the section below More on Component Creator Templates.

Creating Components

Once you have your template set, components can be created with or without variants through menus accessed by right-clicking objects and prims in the Outliner or the Viewport. The method will depend on what kind of data your are starting with:

For Maya objects, select an object in the Outliner or Viewport and choose USD > Create Component. Selecting more than one object will also allow you to create a Component with Variants by choosing USD > Create Component with Variants.

For USD prims, select a prim in the Outliner and choose Create Component, or select two or more prims and choose Create Component with Variants.

More on Component Creator Templates

Overview

The Component Creator output is controlled by options contained in a template file. The file is in JSON format, containing the value for each option.

For Maya, the templates are found in the maya/USDTemplates folder in your "Documents" personal folder. The default template file is generated there the first time the component creator is loaded in Maya.

Template Options

Template options are grouped into four categories:

1. Template description
2. Input modifications
3. File naming
4. USD data structure

Template Description

The following options describe the template itself

Option	Format	Description
options_description	text	Description of the template
options_name	text	Name of the template (must match filename)

Input Modifications

These options modify the input USD data.

Option	Format	Description
at_origin	bool	Clears transforms of root prims
center_component	bool	Centers bounding box at origin
flatten_source	bool	Flattens composition arcs (payloads, references, etc.)

flatten_source Notes The flatten_source option needs more explanation; The component creator always reads the composed opinions of the input file. Internally, it always reduces the local layers in the hierarchy of the input file to a single layer, even when the option is off. The difference is that when the option is turned on, it will also flatten all composition arcs, like payloads, references, inherits, etc. One main consequence of turning the flatten_source option on or off is the handling of payloads and references.

If off, external payloads are kept as payloads, while the local layer stack and opinions are collapsed. One possible consequence is when the local layer stack has variants, but the variant selection affects the contents of the payload; In this case, the local variant selection will be gone in the component, but the variants in the external payloads will still have variant-structured data. When the component loads the payloads, since it does not have the variant selection of the original USD, the payload will use the default selection, which might surprise the user.

If on, the payloads and references will be flattened at the same time as the local layer stack of the input USD. This means that the current variant selection of the input will be used all the way down into the payloads. Thus, the component data will correctly and fully represent the variant that was selected in the input USD. This avoids the surprising effects of the off mode, but the contents of the external payloads are now inside the component and are no longer external payloads.

File Naming

These options control the generation of the filenames of the output component.

Option	Format	Description
file_extension	text	usd / usda / usdc
filename_pattern	text	Root layer filename
payload_filename_pattern	text	Payload filename
scope_layer_filename_pattern	text	Scope layer filename
sub_layers_payload_filename_pattern	text	Sub-layer payload filename

These filename patterns can contain special tokens that get replaced with values derived from the particular component being generated. These tokens are special names contained within curly brackets. For example: {component_name}.

Here is the list of tokens that can be used for filenames: |Token|Documentation| |-----|-------------| |{component_name}|The name of the component| |{component_folder}|The folder containing the component, which itself is a folder| |{component_filename}|The base filename of the root layer of the component| |{file_extension}|The file extension used for USD files as per the file_extension option| |{scope_name}|The name of the scope, for the scope filenames| |{variant_set_name}|The names of all variant sets| |{variant_name}|The names of all variants selected in the variant sets| |{variant_selections}|The variant sets and their selected variants, in pairs| |{object_name}|The name of the selected object from which the component is generated|

USD Data Structure

These options control the structure of the output USD data.

Option	Format	Description
class_prefix_path	SdfPath	Prefix for class names
component_prim_path_pattern	text	Root component path
materials_scope_name	text	Materials scope (e.g., mtl)
meshes_scope_name	text	Mesh scope (e.g., geo)
sub_layers_in_payload	bool	Put sublayers in payload
variant_name_pattern	text	Variant naming
variant_numbered_pattern	text	Numbered variant naming
variant_set_name_pattern	text	Variant set naming
variant_set_numbered_pattern	text	Numbered variant set

The variant set and variant name pattern use the same tokens as the filename patterns described in the previous section. In addition, there is one extra token that can be used for numbered pattern: . This represents a unique number, used to make the variant set name or variant name unique. Note that is uses angle brackets, not curly brackets.

The variant name and variant set patterns are used when there is only a single selected input object used to generate the component. If there are no selected objects or if there are more than one object, then the numbered patterns are used instead.

FAQ

What is the overall USD component file structure? The created component follows the ASWF recommendations about how to structure the data into multiple USD files for clarity and flexibility. Here is the file structure created by the default template, based on the previously described tokens:

component_folder/
  component_name/
    RootLayer.usda
    payload.usda
    geo/
      geo.usda
      variant.usdc
    mtl/
      mtl.usda
      variant.usdc

For example, let’s suppose the tokens values are as follows: |Token|Value| |-----|-----| |{component_name}|NewComponent| |{component_folder}|C:/Data| |{component_filename}|RootLayer| |{file_extension}|usda| |{scope_name}|geo and mtl| |{variant_selections}|variant_set_1 and variant_1| |{object_name}|Building|

Then the file structure would be:

C:/Data
  NewComponent
    RootLayer.usda
    payload.usda
    geo
      geo.usda
      variant_set_1_variant_1.usdc
    mtl
      mtl.usda
      variant_set_1_variant_1.usdc

Why have geo, mtl and bindings sub-layers?

There are multiple reasons to have geo, mtl and bindings sub-layers instead of having the data directly in the root layer of the component.

The first is that it allows a production pipeline to lock these layers when an artist does not have access to, and should not be modifying this data. For example, by locking the material bindings layer, the artist cannot change what materials are assigned to meshes. Similarly, locking the meshes layer, the artist cannot modify the geometry.

The second is that it allows turning off these elements rapidly by muting these layers. For example, muting the material bindings layer removes all materials from all meshes.

Third, it makes the root layer lighter. Currently we have three sub-layers, but we may have other ones in the future. For example, we could add similar sub-layers for lights, special effects, etc. If all that data was in the root layer, it would become very large.