Simple skeletal animation debug viewer for Unity.

HierarchyViewer.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class HierarchyViewer : MonoBehaviour {

    public Material m_Material; //better use a material that disables ZWrite & ZTest.

    class Joint
    {
        public Transform p;
        public Transform c;
        public GameObject hint;
    }

    List<Joint> joints = null;

	// Use this for initialization
	void Start () {

        joints = new List<Joint>();
        Stack<Transform> ts = new Stack<Transform>();
        ts.Push(gameObject.transform);

        while (ts.Count != 0)
        {
            Transform t = ts.Pop();

            int n = t.childCount;
            for (int i = 0; i < n; ++i)
            {
                Transform c = t.GetChild(i);
                GameObject g = GameObject.CreatePrimitive(PrimitiveType.Capsule);
                g.name = c.name + "_VIS";
				g.GetComponent<Renderer>().sharedMaterial = m_Material;

                Joint j = new Joint();
                j.p = t;
                j.c = c;
                j.hint = new GameObject(c.name + "_VIS_PARENT");
		g.transform.parent = j.hint.transform;
                joints.Add(j);
                ts.Push(c);
            }
        }
    }
	
    private void OnEnable()
    {
        if(joints != null)
        {
            for (int i = 0; i < joints.Count; ++i)
            {
                if (joints[i].hint != null)
                    joints[i].hint.GetComponentInChildren<Renderer>().enabled = true;
            }
        }
    }

    private void OnDisable()
    {
        if (joints != null)
        {
            for (int i = 0; i < joints.Count; ++i)
            {
                if (joints[i].hint != null)
                    joints[i].hint.GetComponentInChildren<Renderer>().enabled = false;
            }
        }
    }
	
	// Update is called once per frame
    void Update () {

        for (int i = 0; i < joints.Count; ++i)
        {
            Joint j = joints[i];
            Transform t = j.hint.transform;
            Renderer r = j.hint.GetComponentInChildren<Renderer>();

            Vector3 posP = j.p.position;
            Vector3 posC = j.c.position;

            Vector3 mid = (posC + posP) * 0.5f;
            Vector3 dir = (posC - posP);

            float len = dir.magnitude;
            if (len < 1e-5f || i == 0)
            //	j.hint.HideFlags = HideFlags.HideAndDontSave;
                r.enabled = false;
            //else
            //    j.hint.hideFlags = HideFlags.None;

            //the transform is based on Unity's capsule geometry. (Centered pivot, Y scale doubles the len/height)
	    Transform cap = t.GetChild(0);
            cap.localScale = new Vector3(0.1f, 0.5f, 0.1f) * len;
            cap.localRotation = Matrix4x4.Rotate(j.c.rotation).inverse.rotation * Quaternion.LookRotation(dir.normalized) * Quaternion.FromToRotation(Vector3.forward, Vector3.up);
	    
	    t.rotation = j.c.rotation;
            t.position = mid;
        }
    }
}