The connection between a device axis and an object’s attribute is called an attachment. The attachment informs the device which attribute in the scene you want to change.

Since devices are not defined as dependency graph nodes, their definitions, attachments, and mappings are not saved in Maya files.

Creating an attachments script lets you reload the attribute attachments, command attachments, and mappings when you need them. This saves you having to attach the device to each of its target attributes every time you load a file. You must define the device before running the attachment script.

The MEL script will remake all attribute attachments, command attachments, and mappings, provided the device is defined and the target attributes and nodes have the same names as when you saved the script.

When an attribute attachment is formed, a node (blendDevice) is attached to the target attribute. The blendDevice node determines whether you will view live device data (Enable Monitor) or the animation curve that is attached to the attribute.

In this form, the data is stored in the blendDevice node. Playing over the recorded time range will show the newly recorded data, leaving any animation curves unchanged.