Maya Creative Help | Alembic Export Options

General Options

Cache time range: Select from the following:
Current frame: Caches the current Time Slider frame only.

Current frame: Caches the current Time Slider frame only.
Render settings: Specifies that your current Render settings determine the Cache time range.
Time Slider: Specifies that the current playback range in your Time Slider determines the Cache time range.
Start/End: Specifies that the range of frames between (and including) the specified Start and End times determines the Cache time range.

Step

Specifies how often samples are taken during file creation. By default, one sample of your object's transformations is taken every frame and saved to the Alembic file.

For example, a value of 2 caches the transformations of the current object at every other frame of the Cache Time Range.

Frame relative sample

When on, you can specify the number of samples per frame. You can use this option to set frame sub-sampling data that can be interpreted by rendering applications as shutter opening and closing values for motion blur.

Low/High

Specifies the low and high values for frame relative sampling.

Pre Roll Start Frame

Specifies at which frame to start the scene evaluation. Use this option to set the starting frame for time dependent translations that require a run up to the start frame.

Cache Time Ranges

Use the Cache Time Ranges options to specify multiple time ranges and sampling rates in the same Alembic file. For example in a cache file, you can specify a time range that samples every forth frame of an animation, and then specify another time range that samples every frame. You can use Cache Time Ranges to create a file that saves slow motion sequences at a lower sampling rate, while maintaining high sampling rates for full-action sequences.

Cache Time

Enter the first and last frame of the cache time range. You can also use the Start/End controls to set the time range.

Click Add Range+ to create multiple time ranges.

Pre-Roll

Indicates that a Pre-Roll range is set.

Subsamples

Displays the Frame Relative sample setting for the range.

Attributes

Lets you add dynamic and custom attribute data to the exported Alembic file. To add attributes do one of the following:

Type the name of the attribute in the Attribute field then click Add.
Select an attribute in the Channel Box then click From Channel Box.

Added attributes appear in the table under Attribute.

Attribute Prefix

Specify a prefix to filter out the names of attributes you want written to the Alembic file. Type a value in the Attribute Prefix field and click Add. All of the attributes with the specified prefix in their attribute name are added to the Alembic file.

Advanced Options

Verbose

Outputs frame number information to the Script Editor or output window.

No Normals

Turn on to exclude the source object's normal data from the Alembic cache file.

Renderable Only

Turn on to exclude any non-renderable nodes or hierarchy, such as hidden objects, from the Alembic file.

Strip Namespaces

Turn on to remove the namespaces associated with the exported objects before they are saved to Alembic file. For example, an object with the namespace taco:foo:bar appears as bar in the Alembic file.

UV Write

Turn on to write UV data from polygon meshes and subdivision objects to the Alembic file. Only the current UV map is included.

Write Color Sets

Lets you write color per-vertex data from the source polygon meshes to the Alembic file. You can use this data to export motion vector data from the mesh for motion blur effects at render time.

Turn on Write Color Sets, and then add Motion Vector Color Set to the exported attribute list. To do this, in the Attributes section, type motionVectorColorSet beside Attribute, and then click Add.

Write Face Sets

Turn on to save per-face shading group assignments to the Alembic cache. Maya only saves the shading group names to the file. No material information is written to the cache.

When you load the Alembic file, Maya re-assigns shading to the faces if the shading groups exist in the scene. Maya does not create new materials or shading groups.

Whole Frame Geo

When on, geometry data at whole frames is sampled and written to the file. When off (default), geometry data is sampled at sub-frames and written to the file.

World Space

Turn on to store the top node in the node hierarchy as world space. By default, these nodes are stored as local space.

Write Visibility

Turn on to store the visibility state of objects in the Alembic file. Otherwise, all objects are considered visible.

Filter Euler Rotations

Turn on to filter , X, Y, and Z rotation data with an Euler filter. Euler filtering helps resolve irregularities in rotations especially if X, Y, and Z rotations exceed 360 degrees.

Write Creases

Turn on to export the geometry's edge and vertex crease information to the Alembic file.

Note: See Export creases to an Alembic file for information about exporting crease information to an Alembic file.

File Format

HDF5 - Maya 2014 Extension 1 and Legacy: Creates an Alembic cache file that conforms to the HDF5 data model. This option provides backwards compatibility with previous versions of Alembic.

Ogawa - Maya 2014 Extension 1: Creates an Ogawa Alembic file. Files created with the Ogawa format are smaller in size and provide better performance than legacy Alembic files.

Note: Ogawa Alembic files can only be read by Extension for Maya 2014 and later versions of Maya.

Callbacks

The recommended way to use callbacks with the Alembic export is to first define a global procedure. For example, in the Script Editor, define the following:

global proc perFrameCallback(int $frame) 
{ 
    print $frame; 
}

The full MEL callback is:

perFrameCallback(#FRAME#)

Per Frame Callback MEL: When each frame is evaluated, the string specified is evaluated as a MEL command. For example, print("#FRAME#").
Post Job Callback MEL: When the translation has finished, the string specified is evaluated as a MEL command. For example, print("Done!").
Per Frame Callback Python: When each frame is evaluated, the string specified is evaluated as a Python command. For example, print("#FRAME#").
Post Job Callback Python: When the translation has finished, the string specified is evaluated as a Python command. For example, print("Done!").

Alembic Export Options