I still don't fully understand what the lock mode parameter does. I took my best guess while trying to clarify the documentation on this parameter but I may have gotten it wrong.
Can you confirm any of my revisions?
Quote: " This command will copy the vertex data of the target limb to a buffer, allowing it to be modified by the vertex commands. Changes made while to the buffer will not take effect until it has been unlocked.
If 'LockMode' is set to 0 then a copy of the target limb's mesh will be copied to the buffer.
If 'LockMode' is set to 1 then only the changes between the limb's mesh and the buffer are updated. This can be considerably faster than copying the entire contents of the buffer.
If 'LockMode' is set to 2 then perform a complete copy of the limb's mesh to the buffer. It will also ensure the any changes made between the buffer and the limb itself will be updated as well."
What lock mode 2 is doing, I think, is updating the limb with the difference between the buffer and the mesh data. Sort of like doing an unlock/lock in one command. I'm not sure if that's right though.