Animation Rigging Distance Constraint

DistanceConstraint.cs

public class DistanceConstraint : RigConstraint<DistanceConstraint.Job, DistanceConstraint.Data, DistanceConstraint.Binder>
{
    public struct Job : IWeightedAnimationJob
    {
        public FloatProperty jobWeight { get; set; }
        public ReadOnlyTransformHandle source;
        public ReadWriteTransformHandle target;
        public Vector3 initialTargetLocalPos;
        public float distance;
        public void ProcessRootMotion(AnimationStream stream){}
        public void ProcessAnimation(AnimationStream stream)
        {
            var totalWeight = jobWeight.Get(stream);
            if (totalWeight <= 0f)
                return;
            target.SetLocalPosition(stream, initialTargetLocalPos);
            var sourcePos = source.GetPosition(stream);
            var targetPos = target.GetPosition(stream);
            var currentOffset = targetPos - sourcePos;
            var currentDirection = currentOffset.normalized;
            var newTargetPos = sourcePos + currentDirection * distance;
            target.SetPosition(stream, newTargetPos);
        }
    }
    [System.Serializable]
    public struct Data : IAnimationJobData
    {
        [SyncSceneToStream]
        public Transform source;
        [SyncSceneToStream]
        public Transform target;
        public bool IsValid() => true;
        public void SetDefaultValues()
        {
        }
    }
    public class Binder : AnimationJobBinder<Job, Data>
    {
        public override Job Create(Animator animator, ref Data data, Component component)
        {
            var job = new Job
            {
                source = ReadOnlyTransformHandle.Bind(animator, data.source),
                target = ReadWriteTransformHandle.Bind(animator, data.target),
                distance = Vector3.Distance(data.target.position, data.source.position),
                initialTargetLocalPos = data.target.localPosition,
            };
            return job;
        }
        public override void Destroy(Job job)
        {
        }
    }
}