Transform Cache Constraint
The Transform Cache Constraint is used to stream animations from Alembic or USD made at the transformation matrix level (for example rigid bodies, or camera movements).
When importing an Alembic or USD file, Transform Cache constraints are automatically added to objects with animated transforms. For time-varying meshes (so deforming animations), the Mesh Sequence Cache modifier is used.
- Cache File
Data-block menu to select the Alembic or USD file.
- File Path
Path to the Alembic or USD file.
Whether or not the cache is separated in a series of files.
- Override Frame
Whether to use a custom frame for looking up data in the cache file, instead of using the current scene frame.
The Frame value is the time to use for looking up the data in the cache file, or to determine which to use in a file sequence.
- Frame Offset
Subtracted from the current frame to use for looking up the data in the cache file, or to determine which file to use in a file sequence.
- Manual Scale
Value by which to enlarge or shrink the object with respect to the world’s origin.
- Velocity Attribute
The name of the Alembic attribute used for generating motion blur data; by default, this is
.velocitieswhich is standard for most Alembic files.
The Velocity Attribute option is currently for Alembic files only.
- Velocity Unit
Defines how the velocity vectors are interpreted with regard to time.
The velocity unit was encoded in frames and does not need to be scaled by scene FPS.
The velocity unit was encoded in seconds and needs to be scaled by the scene FPS (1 / FPS).
The Velocity Unit option is currently for Alembic files only.
- Object Path
The path to the Alembic or USD object inside the archive or stage.
Controls the percentage of affect the constraint has on the object. See common constraint properties for more information.