Scripted mesh combine with animation such as Armor, Clothing, etc.

Just to get everyone on the same page, I am not interested in an external bundle or plugin from the Asset Store to resolve this issue. I am not a fan of the 'answer your question with a purchase' mentality.

I have several skinned meshes which have a weight table, and are animated(created with 3ds Max). I have split these meshes up, so they could be re-combined through code, to create a variety of armor configurations.

Think of your typical RPG, where a user could have several options for helms, tunics, boots, pants, etc.

I've already found a solution to my issue, but I'm wanting to know if there is a BETTER solution. The way I have done this was tedious, and knowing Unity, there should be a built in way to do this without so much hassle on my end. I also wanted to post this, in case there are others out there, like myself, who wanted to do this, but couldn't find a way.

Here is a script I wrote to output the bones for the child mesh:

 using UnityEngine;
 
 public class DiscoverBones : MonoBehaviour {
 
     // Use this for initialization
     void Start () {
         Debug.Log ("**** Bone discovery ****");
         SkinnedMeshRenderer smr = gameObject.GetComponent<SkinnedMeshRenderer>();
         for (int i = 0; i < smr.bones.Length; i++) {
             Debug.Log ("Bone:"+i+"|"+smr.bones[i].name);
         }
         Debug.Log ("--- end ---");
     }
 }

This will output something like this:

**** Bone discovery ****

Bone:0|Bip01 L Clavicle

Bone:1|Bip01 Spine1

Bone:2|Bip01 Spine

Bone:3|Bip01 R Clavicle

Bone:4|Bip01 Pelvis

Bone:5|Bip01 L UpperArm

Bone:6|Bip01 R UpperArm

--- end ---

Once I record the bones, I remove the DiscoverBones script, then I can remove the mesh from the skeleton, add it as a prefab, and reference it with this script:

 using UnityEngine;
 
 public enum MeshSlot
 {
     Head = 1,
     Chest = 2,
     Arms = 4,
     Skirt = 8,
     SleeveCuff = 16,
     Hands = 32,
     GloveCuff = 64,
     Legs = 128,
     Shins = 256,
     Boots = 512,
     BootCuff = 1024
 };
 
 public class ArmorPiece : MonoBehaviour {
     
     public MeshSlot slotMask;
     public GameObject Prefab; // reference to the Child Mesh from above...
     public string[] Bones;
     public int RootBone;
     public Texture Texture;
 }

In this script, I take the bones listed in the DiscoverBones output, and put it in the Bones array. I also put in the RootBone.

So now I can call this function on the original parent object with the skeleton, passing in the prefab with the ArmorPiece attached to it:

 // root mesh GameObject of the original imported mesh (the one with the Animator)
 public Transform MyMesh; 
 public Transform Biped; // the biped GameObject imported
 
 private void CreateNewArmorMesh( ArmorPiece armorPiece){
     SkinnedMeshRenderer armorRef = armorPiece.Prefab.GetComponent<SkinnedMeshRenderer> ();
     var NewObj = new GameObject( armorRef.gameObject.name );
     NewObj.transform.parent = MyMesh.transform;
     var NewRenderer = NewObj.AddComponent<SkinnedMeshRenderer>();
 
     Transform[] boneMap = new Transform[armorRef.bones.Length];
 
     for( int i = 0; i < armorPiece.Bones.Length; i++){
         boneMap[i] = FindChildByName(armorPiece.Bones[i], Biped);
     }
 
     NewRenderer.bones = boneMap;
     NewRenderer.sharedMesh = armorRef.sharedMesh;
     NewRenderer.sharedMaterials = armorRef.sharedMaterials;
     NewRenderer.material.SetTexture ("_MainTex", armorPiece.Texture);
     NewRenderer.rootBone = boneMap[armorPiece.RootBone];
 }
 
 private Transform FindChildByName( string ThisName, Transform ThisGObj ){
     Transform ReturnObj = null;
     if (ThisGObj.name == ThisName) {
         return ThisGObj.transform;
     }
     foreach ( Transform child in ThisGObj )
     {
         ReturnObj = FindChildByName( ThisName, child );
         if( ReturnObj ){
             return ReturnObj;
         }
     }
     return null;
 }

As you can see, this is a real hassle, and not something easy to understand how to do if you're new to Unity. I figured there might be some setting or a way to reference the original mesh for the prefab. I just don't know enough about Unities animation and render system to know where to look.