Pipeline Cache > Alembic Cache > Export

General Options

Cache time range

Select from the following:

Evaluate every

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.

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

When on, normal data from the original polygon objects is not included in the exported Alembic cache file.

Renderable Only

When on, any non-renderable nodes or hierarchy, such as hidden objects, are not included in the Alembic file.

Strip Namespaces

When on, any namespaces associated with the exported objects are removed from the Alembic file. For example, an object with the namespace taco:foo:bar appears as bar in the Alembic file.

UV Write

When on, UV data from polygon meshes and subdivision objects are written to the Alembic file. Only the current UV map is included.

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

When on, the top node in the node hierarchy is stored as world space. By default, these nodes are stored as local space.

Write Visibility

When on, the visibility state of objects is stored in the Alembic file. Otherwise, all objects are considered visible.

Filter Euler Rotations

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

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!").