Unity动画丨4. 混合树的几种类型Blend Tree—Blend Type

2D Simple Directional: Best used when your motions represent（表现） different directions, such as “walk forward”, “walk backward”, “walk left”, and “walk right”, or “aim up”, “aim down”, “aim left”, and “aim right”. Optionally（随意的） a single（单一的） 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”（不应是同方向上的多个不同动作，比如“向前走”和“向前跑”）.

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（不代表不同的方向）. With Freeform Cartesian your X parameter and Y parameter can represent different concepts（概念）, such as angular speed（角速度） and linear speed（线速度）. An example would be motions such as “walk forward no turn”, “run forward no turn”, “walk forward turn right”（向前走，只是头部向右望，身体依旧向前走）, “run forward turn right” etc.

Direct: This type of blend tree lets user control the weight of each node directly. Useful for facial shapes or random idle blending. 

X、Y的Position From需要根据需要需要选择计算。