3.Blend Trees

Blend Trees

Blend Trees are used for allowing multiple animations to be blended smoothly by incorporating parts of them all to varying degrees. The amount that each of the motions contributes to the final effect is controlled using a blending parameter, which is just one of the numeric animation parameters associated with the Animator Controller. In order for the blended motion to make sense, the motions that are blended must be of similar nature and timing. Blend Trees are a special type of state in an Animation State Machine.

Right click on the empty space > Select Create State > From New Blend Tree from the context menu that appears.

This create a state that have Blend trees as it motion. Double click on before will allow you to edit it.

This is where you will edit the Blend Tree and the Blend type for this is 1D (1 Dimensional Blend Tree)

1 D Blend tree use a single parameter to control how much motion should be play. 

This is the list of motion. To add motion click the plus icon and choose Add Motion Field

To add the motion you can either drag from the asset list or click circle select button

This blue cross diagram is the illustration of where the different motion lies on the scale of parameter.
The lowest threshold is on the left and highest on the right.

Automate Threshold is check then the threshold that you had for each animation is set and wont be changeable.
 If uncheck, we can use the following tools option. Compute Thresholds will calculate and set threshold base on your motion field. It will do this base on root motion that  you will select.

Adjust Time Scale you can make the speed homogeneous speed or reset time scale.

There are 3 type of 2D Blend tree.

2D Simple Directional: Best used when your motions represent different directions, such as “walk forward”, “walk backward”, “walk left”, and “walk right”, or “aim up”, “aim down”, “aim left”, and “aim right”. Optionally a single motion at position (0, 0) can be included, such as “idle” or “aim straight”. In the Simple Directional type there should not be multiple motions in the same direction, such as “walk forward” and “run forward”.
2D Freeform Directional: This blend type is also used when your motions represent different directions, however you can have multiple motions in the same direction, for example “walk forward” and “run forward”. In the Freeform Directional type the set of motions should always include a single motion at position (0, 0), such as “idle”.
2D Freeform Cartesian: Best used when your motions do not represent different directions. With Freeform Cartesian your X parameter and Y parameter can represent different concepts, such as angular speed and linear speed. An example would be motions such as “walk forward no turn”, “run forward no turn”, “walk forward turn right”, “run forward turn right” etc.

The view of 2D Simple Directional.