--This script will remove dead (unused) sections of a bone hierarchy from a skin. 
--It will not remove a bone if any decendants of the bone is in use.

idxIsClothCollision = ( GetAttrIndex "Gta Collision" "Is Cloth Collision" )

fn findRemoveBoneList obj =
(
	skinMod = obj.modifiers[#Skin]
	select obj
	max modify mode
	totalBones = skinOps.getNumberBones skinMod
	
	boneNameRemovalList = #()
	for boneID = 1 to totalBones do 
	(
		if ( boneIsNotUsed obj boneID skinMod ) then
		(
			boneName = skinOps.GetBoneName skinMod boneID 1			
			appendIfUnique boneNameRemovalList boneName
		)
	)
	
	for boneName in boneNameRemovalList do
	(
		boneNode = GetNodeByName boneName
		if not ( IsValidNode thisBoneNode ) then continue
	
		if( allDecendentsAreMarkedForRemoval ) then
		(
			print ("Removing "+boneName+" from "+obj.name)
			
			matchingBoneID = -1
			for queryBoneID = 1 to totalBones do
			(
				queryBoneName = skinOps.GetBoneName skinMod queryBoneID 1
				if( queryBoneName == boneName ) then
				(
					matchingBoneID = queryBoneID
					exit
				)
			)			
			
			if( matchingBoneID != -1 ) then
			(
				skinOps.SelectBone skinMod matchingBoneID
				skinOps.removebone skinMod
			)
		)
	)
)

fn allDecendentsAreMarkedForRemoval obj matchNameArray =
(
	for child in obj.children do
	(
		if not( contains matchNameArray child.name ) then
		(
			return False
		)
		
		if not( allDecendentsAreMarkedForRemoval child matchNameArray ) then
		(
			return False
		)
	)
	
	return True
)

fn boneIsNotUsed obj boneID skinMod =
(
	thisBoneName = skinOps.GetBoneName skinMod boneID 1
	thisBoneNode = GetNodeByName thisBoneName
	
	--Check to see if the bone has cloth collision added to it
	if( IsValidNode thisBoneNode ) then
	(
		for child in thisBoneNode.children do
		(
			if( GetAttrClass child == "Gta Collision" ) then
			(
				if( GetAttr child idxIsClothCollision ) then
				(	
					return False
				)
			)
		)
	)
	
	totalVerts = skinOps.getNumberVertices skinMod
	for v = 1 to totalVerts do --now we test each vert and see if this bones is weighted to it
	(
		weightCount = skinOps.GetVertexWeightCount skinMod v --first get the no of influences on this vert
		
		for vB = 1 to weightCount do 
		(
			tB = skinOps.getVertexWeightBoneID skinMod v vB
			
			if tB == boneID do --this means we have found the match to the skinModBones bones we are on
			(
				vtWeight = skinOps.getVertexWeight skinMod v vB
				
				if vtWeight != undefined do 
				(
					if vtWeight >= 0.0 do 
					(
						return False
					)
				)
			)
		)
	)
	
	return True
)

selA = selection as array

for a = 1 to sela.count do 
(
	if sela[a].modifiers[#Skin] != undefined do 
	(
		try (findRemoveBoneList sela[a]) catch (Print (sela[a].name+" has a prob!"))
	)
-- 	messagebox ("Removal COMPLETE!") beep:true
)
messagebox ("Removal COMPLETE!") beep:true