左足の底の位置の高さを取得します
void LateUpdate()
{
if(animator)
{
Vector3 leftFootT = animator.GetIKPosition(AvatarIKGoal.LeftFoot);
Quaternion leftFootQ = animator.GetIKRotation(AvatarIKGoal.LeftFoot);
Vector3 leftFootH = new Vector3(0, -animator.leftFeetBottomHeight, 0);
Vector3 pos = leftFootT + leftFootQ * leftFootH;
Debug.Log(pos);
}
}