Animation Parameters

Animation Parameters are variables that are defined within the animation system but can also be accessed and assigned values from scripts. For example, the value of a parameter can be updated by an animation curve and then accessed from a script so that, say, the pitch of a sound effect can be varied as if it were a piece of animation. Likewise, a script can set parameter values to be picked up by Mecanim. For example, a script can set a parameter to control a Blend Tree.

Default parameter values can be set up using the Parameters widget in the bottom left corner of the Animator window. They can be of five basic types:

• Int - an integer (whole number)
• Float - a number with a fractional part
• Bool - true or false value
• Trigger - a boolean parameter that is reset by the controller when consumed by a transition.

Parameters can be assigned values from a script using functions in the Animator class: SetFloat, SetInt, and SetBool.

Here’s an example of a script that modifies parameters based on user input

using UnityEngine;
using System.Collections;


public class AvatarCtrl : MonoBehaviour {

    protected Animator animator;
    
    public float DirectionDampTime = .25f;
    
    void Start () 
    {
        animator = GetComponent<Animator>();
    }
    
    void Update () 
    {
        if(animator)
        {
            //get the current state
            AnimatorStateInfo stateInfo = animator.GetCurrentAnimatorStateInfo(0);
            
            //if we're in "Run" mode, respond to input for jump, and set the Jump parameter accordingly. 
            if(stateInfo.nameHash == Animator.StringToHash("Base Layer.RunBT"))
            {
                if(Input.GetButton("Fire1")) 
                    animator.SetBool("Jump", true );
            }
            else
            {
                animator.SetBool("Jump", false);                
            }
            
            float h = Input.GetAxis("Horizontal");
            float v = Input.GetAxis("Vertical");
            
            //set event parameters based on user input
            animator.SetFloat("Speed", h*h+v*v);
            animator.SetFloat("Direction", h, DirectionDampTime, Time.deltaTime);
        }       
    }        
}