If it makes it easier to understand
An animation BP contains an animgraph where the migration path is created in two sections.
Section 1 is generally called the locomotion state usually built using blend spaces and state machines which determines how the player moves in 3d space. This will be your runs, walks, crouch, swim, climbing, flying or in general anything where the player needs to move. More or less locomotion involves animation be applied to the player model from toes to nose.
Section 2 is the action state where the animation is layered using a per bone blend that adds the animation to a selected bone, the first joint above the hips, where the animation overrides the animation applied in the locomotion section that involves states like like reloading a weapon, punching, or waving hello or any action where the player is not required to be moving.
The result is the player now has the ability to combine two states at the same time as in being able to walk and preform an action at the same time like walking and waving with out having to make unique animations as a single state, like a single animation of the player walking and waving.
Using this kind of setup one can account for any kind of animation combination and keep the animation requirements down to what is needed to move the player or trigger any action state with out consideration as to the current locomotion state.
The action state is where montages shine as the player can only be in one action state at any give time so the migration requirements usually involves just three components.
- A cached state coming from the locomotion section.
- A per bone layer
- A montage slot.
The rest of the work is done in the eventgraph as once you make the montage and assign it to a slot you can add the montage “name” to a list in the eventgraph and when triggered the slot will pick it up base on the slot the montage is assigned to.
Some other advantages.
A montage will play from start to end once activated. If you are reloading by pressing R you don’t have to hold the R button as you would using a button to move forward for example.
A montage can be locked in until it’s completed or overridden if another montage is activated.
A montage can be passed much easier from one BP to another with out consideration as to unique takes. Think of a montage as a package that fits in a single channel as to managing the action and not so much that the montage contains an action state like waving hello.
So rule of thumb if you want to add an action state consider a montage as it cuts the management and animation requirements down to next to nothing as compared to using individual takes.