第一步创建动画层

第二步添加遮罩Avatar Mask

第三步设置权重

模型上的源码：

using UnityEngine;
using System.Collections;

public class AvatarMaskTest : MonoBehaviour {

    private Animator m_animator;
    // Use this for initialization
    void Start () {
        m_animator = this.GetComponent<Animator>();
    }

    // Update is called once per frame
    void Update () {
        if (Input.GetKeyDown(KeyCode.R))
        {
            m_animator.SetBool("run",true);
        }
        if (Input.GetKeyUp(KeyCode.R))
        {
            m_animator.SetBool("run", false);
        }

        if (Input.GetKeyDown(KeyCode.J))
        {
            m_animator.SetBool("jump", true);
        }
        if (Input.GetKeyUp(KeyCode.J))
        {
            m_animator.SetBool("jump", false);
        }
        if (Input.GetKeyDown(KeyCode.W))
        {
            m_animator.SetBool("wave", true);
        }
        if (Input.GetKeyUp(KeyCode.W))
        {
            m_animator.SetBool("wave", false);
        }
    }
}

动画效果：