I started this as an edit to an above post, regarding the ranges of animation ID values, but it started getting long so I moved it down here. :-)
If you REALLY wanted to, you could only have character-specific animations in the Animator belonging to that specific character. However, this is a lot of extra work and you lose the ability to use an Override Animator (as you can only substitute animation clips; you can't even look at the animation state machines, much less modify them).
My first thought was to divide the animation IDs according to which character they're for. It might be a better approach to group the animation IDs according to which cutscene they're used in. Either way, you could use certain digits in the ID to encode useful data. For example, going from right-to-left:
Two digits for the specific animation
One or two digits to designate a specific actor in a cutscene
Two or three digits to designate the specific cutscene
One digit designating that this is a cutscene animation
How many digits you use and how narrow the categories are is entirely dependent on the scope of your game and the number of animations you have.
For example, when I see the
cutsceneAnimID 1780122, I know that it is not some random, meaningless value:
It is a cutscene animation (1xxxxxx)
It is used in cutscene
#78 (178xxxx)
It is used by the first actor in the Game Event playing the sequence, probably the player (1xx01xx)
To take it a step further, we could also state that values for cutscene
#00 (100xxxx) are animations that are used in multiple cutscenes. Actor
#00 (1xx00xx) means that the animations are used by multiple actors. If we have more than 100 animations that are used by multiple actors in multiple cutscenes, then we'll need to re-think our ranges a bit.
It is a bit of a hassle to use IDs like this for animations, rather than bool or trigger parameters that are written in plain English, but I'm sure you don't want a list of 100+ parameters in your Animator either. Just make sure you keep track of your list of animations and their IDs in a spreadsheet, and you're good.
This approach is likely a bit heavy-handed for very simple Animators, but it scales up very nicely, whereas adding more and more parameters and more transitions from
Any State scales up rather poorly.