DeltaVR3DModelGeneration/Assets/_PROJECT/Scripts/NPCController.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using DG.Tweening;

public class NPCController : MonoBehaviour
{
    private Vector3 mouthClosedScale;
    private Vector3 mouthOpenScale;
    private bool isTalking;

    public Transform mouthTransform;
    public float mouthScalingMultiplier = 2.5f;
    public float mouthMovementDuration = 0.25f;

    // Start is called before the first frame update
    void Awake()
    {
        mouthClosedScale = mouthTransform.localScale;
        mouthOpenScale = new Vector3(mouthClosedScale.x, mouthClosedScale.y * mouthScalingMultiplier, mouthClosedScale.z);

        isTalking = false;
    }

    // Update is called once per frame
    void Update()
    {
        
    }

    public void StartTalking()
    {
        isTalking = true;
        MoveMouth();
    }

    public void Stoptalking()
    {
        isTalking = false;
    }


    private void MoveMouth()
    {
        if (!isTalking)
        {
            return;
        }

        if (mouthTransform.localScale == mouthClosedScale)
        {
            mouthTransform.DOScale(mouthOpenScale, mouthMovementDuration);
        }
        else
        {
            mouthTransform.DOScale(mouthClosedScale, mouthMovementDuration);
        }

        Invoke("MoveMouth", mouthMovementDuration + 0.01f);
    }
}