diff --git a/game/client/c_baseanimating.cpp b/game/client/c_baseanimating.cpp
index 97634c31ae..5d26f52bbf 100644
--- a/game/client/c_baseanimating.cpp
+++ b/game/client/c_baseanimating.cpp
@@ -12,6 +12,7 @@
 #include "convar.h"
 #include "iconvar.h"
 #include "interpolatedvar.h"
+#include "mathlib/mathlib.h"
 #include "model_types.h"
 #include "bone_setup.h"
 #include "ivrenderview.h"
@@ -1498,7 +1499,7 @@ void C_BaseAnimating::BuildTransformations( CStudioHdr *hdr, Vector *pos, Quater
 				m_pBoneMergeCache = new CBoneMergeCache;
 				m_pBoneMergeCache->Init( this );
 			}
-			m_pBoneMergeCache->MergeMatchingBones( boneMask );
+			m_pBoneMergeCache->MergeMatchingBones( boneMask, m_BoneAccessor.GetBoneArrayForWrite() );
 		}
 		else
 		{
@@ -1890,7 +1891,7 @@ void C_BaseAnimating::AccumulateLayers( IBoneSetup &boneSetup, Vector pos[], Qua
 
 void C_BaseAnimating::ChildLayerBlend( Vector pos[], Quaternion q[], float currentTime, int boneMask )
 {
-	return;
+    return;
 
 	Vector		childPos[MAXSTUDIOBONES];
 	Quaternion	childQ[MAXSTUDIOBONES];
@@ -2743,82 +2744,6 @@ void C_BaseAnimating::ThreadedBoneSetup()
 	g_PreviousBoneSetups.RemoveAll();
 }
 
-void C_BaseAnimating::BuildMatricesWithBoneMerge( 
-	const CStudioHdr *pStudioHdr,
-	const QAngle& angles, 
-	const Vector& origin, 
-	const Vector pos[MAXSTUDIOBONES],
-	const Quaternion q[MAXSTUDIOBONES],
-	matrix3x4_t bonetoworld[MAXSTUDIOBONES],
-	C_BaseAnimating *pParent,
-	CBoneCache *pParentCache
-	)
-{
-	CStudioHdr *fhdr = pParent->GetModelPtr();
-	mstudiobone_t *pbones = pStudioHdr->pBone( 0 );
-
-	matrix3x4_t rotationmatrix; // model to world transformation
-	AngleMatrix( angles, origin, rotationmatrix);
-
-	for ( int i=0; i < pStudioHdr->numbones(); i++ )
-	{
-		// Now find the bone in the parent entity.
-		bool merged = false;
-		int parentBoneIndex = Studio_BoneIndexByName( fhdr, pbones[i].pszName() );
-		if ( parentBoneIndex >= 0 )
-		{
-			matrix3x4_t *pMat = pParentCache->GetCachedBone( parentBoneIndex );
-			if ( pMat )
-			{
-				MatrixCopy( *pMat, bonetoworld[ i ] );
-				merged = true;
-			}
-		}
-
-		if ( !merged )
-		{
-			// If we get down here, then the bone wasn't merged.
-			matrix3x4_t bonematrix;
-			QuaternionMatrix( q[i], pos[i], bonematrix );
-
-			if (pbones[i].parent == -1) 
-			{
-				ConcatTransforms (rotationmatrix, bonematrix, bonetoworld[i]);
-			} 
-			else 
-			{
-				ConcatTransforms (bonetoworld[pbones[i].parent], bonematrix, bonetoworld[i]);
-			}
-		}
-	}
-}
-
-void C_BaseAnimating::GetSkeleton( CStudioHdr *pStudioHdr, Vector pos[], Quaternion q[], int boneMask, float currentTime )
-{
-	if(!pStudioHdr)
-	{
-		Assert(!"C_BaseAnimating::GetSkeleton() without a model");
-		return;
-	}
-
-	IBoneSetup boneSetup( pStudioHdr, boneMask, m_flPoseParameter );
-	boneSetup.InitPose( pos, q );
-
-	boneSetup.AccumulatePose( pos, q, GetSequence(), GetCycle(), 1.0, currentTime, m_pIk );
-
-	if ( m_pIk )
-	{
-		CIKContext auto_ik;
-		auto_ik.Init( pStudioHdr, GetRenderAngles(), GetRenderOrigin(), currentTime, 0, boneMask );
-		boneSetup.CalcAutoplaySequences( pos, q, currentTime, &auto_ik );
-	}
-	else
-	{
-		boneSetup.CalcAutoplaySequences( pos, q, currentTime, NULL );
-	}
-	boneSetup.CalcBoneAdj( pos, q, m_flEncodedController );
-}
-
 bool C_BaseAnimating::SetupBones( matrix3x4_t *pBoneToWorldOut, int nMaxBones, int boneMask, float currentTime )
 {
 	VPROF_BUDGET( "C_BaseAnimating::SetupBones", VPROF_BUDGETGROUP_CLIENT_ANIMATION );
diff --git a/game/client/c_baseanimating.h b/game/client/c_baseanimating.h
index 0d9fb02190..4cb2a00bfc 100644
--- a/game/client/c_baseanimating.h
+++ b/game/client/c_baseanimating.h
@@ -144,11 +144,6 @@ public:
  	virtual int	VPhysicsGetObjectList( IPhysicsObject **pList, int listMax );
 
 	// model specific
-	void BuildMatricesWithBoneMerge( const CStudioHdr *pStudioHdr, const QAngle& angles, 
-		const Vector& origin, const Vector pos[MAXSTUDIOBONES],
-		const Quaternion q[MAXSTUDIOBONES], matrix3x4_t bonetoworld[MAXSTUDIOBONES],
-		CBaseAnimating *pParent, CBoneCache *pParentCache );
-	virtual	void GetSkeleton( CStudioHdr *pStudioHdr, Vector pos[], Quaternion q[], int boneMask, float currentTime );
 	virtual bool SetupBones( matrix3x4_t *pBoneToWorldOut, int nMaxBones, int boneMask, float currentTime );
 	virtual void UpdateIKLocks( float currentTime );
 	virtual void CalculateIKLocks( float currentTime );
diff --git a/game/client/c_baseanimatingoverlay.cpp b/game/client/c_baseanimatingoverlay.cpp
index 4f9dc37bd4..1ea6b99062 100644
--- a/game/client/c_baseanimatingoverlay.cpp
+++ b/game/client/c_baseanimatingoverlay.cpp
@@ -370,66 +370,3 @@ CStudioHdr *C_BaseAnimatingOverlay::OnNewModel()
 
 	return hdr;
 }
-
-void C_BaseAnimatingOverlay::GetSkeleton( CStudioHdr* pStudioHdr, Vector pos[], Quaternion q[], int boneMask, float currentTime )
-{
-	if(!pStudioHdr)
-	{
-		Assert(!"C_BaseAnimating::GetSkeleton() without a model");
-		return;
-	}
-
-	if (!pStudioHdr->SequencesAvailable())
-	{
-		return;
-	}
-
-	float poseparameters[MAXSTUDIOPOSEPARAM];
-	GetPoseParameters(pStudioHdr, poseparameters);
-
-	IBoneSetup boneSetup( pStudioHdr, boneMask, poseparameters );
-	boneSetup.InitPose( pos, q );
-
-	boneSetup.AccumulatePose( pos, q, GetSequence(), GetCycle(), 1.0, currentTime, m_pIk );
-
-	// sort the layers
-	int layer[MAX_OVERLAYS] = {};
-	int i;
-	for (i = 0; i < m_AnimOverlay.Count(); i++)
-	{
-		layer[i] = MAX_OVERLAYS;
-	}
-	for (i = 0; i < m_AnimOverlay.Count(); i++)
-	{
-		CAnimationLayer &pLayer = m_AnimOverlay[i];
-		if( (pLayer.m_flWeight > 0) && pLayer.IsActive() && pLayer.m_nOrder >= 0 && pLayer.m_nOrder < m_AnimOverlay.Count())
-		{
-			layer[pLayer.m_nOrder] = i;
-		}
-	}
-	for (i = 0; i < m_AnimOverlay.Count(); i++)
-	{
-		if (layer[i] >= 0 && layer[i] < m_AnimOverlay.Count())
-		{
-			CAnimationLayer &pLayer = m_AnimOverlay[layer[i]];
-			// UNDONE: Is it correct to use overlay weight for IK too?
-			boneSetup.AccumulatePose( pos, q, pLayer.m_nSequence, pLayer.m_flCycle, pLayer.m_flWeight, currentTime, m_pIk );
-		}
-	}
-
-	if ( m_pIk )
-	{
-		CIKContext auto_ik;
-		auto_ik.Init( pStudioHdr, GetRenderAngles(), GetRenderOrigin(), currentTime, 0, boneMask );
-		boneSetup.CalcAutoplaySequences( pos, q, currentTime, &auto_ik );
-	}
-	else
-	{
-		boneSetup.CalcAutoplaySequences(pos, q, currentTime, NULL);
-	}
-
-	float controllers[MAXSTUDIOBONECTRLS];
-	GetBoneControllers(controllers);
-
-	boneSetup.CalcBoneAdj( pos, q, controllers );
-}
\ No newline at end of file
diff --git a/game/client/c_baseanimatingoverlay.h b/game/client/c_baseanimatingoverlay.h
index f82def41b1..e8527df5b9 100644
--- a/game/client/c_baseanimatingoverlay.h
+++ b/game/client/c_baseanimatingoverlay.h
@@ -38,8 +38,6 @@ public:
 	// model specific
 	virtual void	AccumulateLayers( IBoneSetup &boneSetup, Vector pos[], Quaternion q[], float currentTime );
 	virtual void DoAnimationEvents( CStudioHdr *pStudioHdr );
-	virtual	void GetSkeleton( CStudioHdr *pStudioHdr, Vector pos[], Quaternion q[], int boneMask, float currentTime );
-
 	enum
 	{
 		MAX_OVERLAYS = 15,
diff --git a/game/client/client_base.vpc b/game/client/client_base.vpc
index 90e16cb81d..24f145928b 100644
--- a/game/client/client_base.vpc
+++ b/game/client/client_base.vpc
@@ -204,7 +204,7 @@ $Project
 		$File	"beamdraw.cpp"
 		$File	"$SRCDIR\game\shared\beam_shared.cpp"
 		$File	"$SRCDIR\public\bone_accessor.cpp"
-		$File	"bone_merge_cache.cpp"
+		$File	"$SRCDIR\game\shared\bone_merge_cache.cpp"
 		$File	"c_ai_basehumanoid.cpp"
 		$File	"c_ai_basenpc.cpp"
 		$File	"c_baseanimating.cpp"
@@ -674,7 +674,7 @@ $Project
 		$File	"baseanimatedtextureproxy.h"
 		$File	"baseclientrendertargets.h"
 		$File	"beamdraw.h"
-		$File	"bone_merge_cache.h"
+		$File	"$SRCDIR\game\shared\bone_merge_cache.h"
 		$File	"c_ai_basenpc.h"
 		$File	"c_baseanimating.h"
 		$File	"c_baseanimatingoverlay.h"
diff --git a/game/client/cstrike/c_cs_player.cpp b/game/client/cstrike/c_cs_player.cpp
index 6c618cd771..e63fa5bc99 100644
--- a/game/client/cstrike/c_cs_player.cpp
+++ b/game/client/cstrike/c_cs_player.cpp
@@ -2598,103 +2598,12 @@ float C_CSPlayer::GetDeathCamInterpolationTime()
 		return spec_freeze_time.GetFloat();
 	else
 		return CS_DEATH_ANIMATION_TIME;
-
 }
 
-ConVar cl_server_setup_bones("cl_server_setup_bones", "1");
 
 bool C_CSPlayer::SetupBones( matrix3x4_t *pBoneToWorldOut, int nMaxBones, int boneMask, float currentTime )
 {
-	if (cl_server_setup_bones.GetBool())
-	{
-		AUTO_LOCK( m_BoneSetupLock );
-
-		MDLCACHE_CRITICAL_SECTION();
-
-		Assert( GetModelPtr() );
-
-		CStudioHdr *pStudioHdr = GetModelPtr( );
-
-		if(!pStudioHdr)
-		{
-			Assert(!"C_BaseAnimating::GetSkeleton() without a model");
-			return false;
-		}
-
-		Assert( !IsEFlagSet( EFL_SETTING_UP_BONES ) );
-
-		AddEFlags( EFL_SETTING_UP_BONES );
-
-		Vector pos[MAXSTUDIOBONES];
-		Quaternion q[MAXSTUDIOBONES];
-
-		// adjust hit boxes based on IK driven offset
-		Vector adjOrigin = GetRenderOrigin();
-
-		if ( m_pIk )
-		{
-			// FIXME: pass this into Studio_BuildMatrices to skip transforms
-			CBoneBitList boneComputed;
-			m_iIKCounter++;
-			m_pIk->Init( pStudioHdr, GetRenderAngles(), adjOrigin, currentTime, m_iIKCounter, boneMask );
-			GetSkeleton( pStudioHdr, pos, q, boneMask, currentTime );
-
-			m_pIk->UpdateTargets( pos, q, m_BoneAccessor.GetBoneArrayForWrite(), boneComputed );
-			CalculateIKLocks( currentTime );
-			m_pIk->SolveDependencies( pos, q, m_BoneAccessor.GetBoneArrayForWrite(), boneComputed );
-		}
-		else
-		{
-			// Msg( "%.03f : %s:%s\n", gpGlobals->curtime, GetClassname(), GetEntityName().ToCStr() );
-			GetSkeleton( pStudioHdr, pos, q, boneMask, currentTime );
-		}
-		
-		CBaseAnimating *pParent = dynamic_cast< CBaseAnimating* >( GetMoveParent() );
-		if ( pParent )
-		{
-			// We're doing bone merging, so do special stuff here.
-			CBoneCache *pParentCache = pParent->GetBoneCache(pParent->GetModelPtr());
-			if ( pParentCache )
-			{
-				BuildMatricesWithBoneMerge( 
-					pStudioHdr, 
-					GetRenderAngles(), 
-					adjOrigin, 
-					pos, 
-					q, 
-					m_BoneAccessor.GetBoneArrayForWrite(), 
-					pParent, 
-					pParentCache );
-				
-				RemoveEFlags( EFL_SETTING_UP_BONES );
-				return true;
-			}
-		}
-
-		Studio_BuildMatrices( 
-			pStudioHdr, 
-			GetRenderAngles(), 
-			adjOrigin, 
-			pos, 
-			q, 
-			-1,
-			GetModelScale(), // Scaling
-			m_BoneAccessor.GetBoneArrayForWrite(),
-			boneMask );
-
-		RemoveEFlags(EFL_SETTING_UP_BONES);
-
-		if ( pBoneToWorldOut )
-		{
-			memcpy( pBoneToWorldOut, m_BoneAccessor.GetBoneArrayForWrite(), sizeof( matrix3x4_t ) * MAXSTUDIOBONES );
-		}
-
-        return true;
-	}
-	else
-	{
-		return BaseClass::SetupBones( pBoneToWorldOut, nMaxBones, boneMask, currentTime );
-	}
+	return BaseClass::SetupBones( pBoneToWorldOut, nMaxBones, boneMask, currentTime );
 }
 
 //=============================================================================
diff --git a/game/server/BaseAnimatingOverlay.cpp b/game/server/BaseAnimatingOverlay.cpp
index 36534bc0fa..2a969ba9fb 100644
--- a/game/server/BaseAnimatingOverlay.cpp
+++ b/game/server/BaseAnimatingOverlay.cpp
@@ -447,7 +447,12 @@ void CBaseAnimatingOverlay::GetSkeleton( CStudioHdr *pStudioHdr, Vector pos[], Q
 		return;
 	}
 
-	IBoneSetup boneSetup( pStudioHdr, boneMask, GetPoseParameterArray() );
+    float flPoseParams[MAXSTUDIOPOSEPARAM];
+    float flEncodedParams[MAXSTUDIOBONECTRLS];
+
+    GetPoseParameters( pStudioHdr, flPoseParams );
+
+	IBoneSetup boneSetup( pStudioHdr, boneMask, flPoseParams );
 	boneSetup.InitPose( pos, q );
 
 	boneSetup.AccumulatePose( pos, q, GetSequence(), GetCycle(), 1.0, gpGlobals->curtime, m_pIk );
@@ -486,12 +491,12 @@ void CBaseAnimatingOverlay::GetSkeleton( CStudioHdr *pStudioHdr, Vector pos[], Q
 	else
 	{
 		boneSetup.CalcAutoplaySequences( pos, q, gpGlobals->curtime, NULL );
-	}
-	boneSetup.CalcBoneAdj( pos, q, GetEncodedControllerArray() );
+    }
+    GetEncodedControllers( pStudioHdr, flEncodedParams );
+	boneSetup.CalcBoneAdj( pos, q, flEncodedParams );
 }
 
 
-
 //-----------------------------------------------------------------------------
 // Purpose: zero's out all non-restore safe fields
 // Output :
diff --git a/game/server/baseanimating.cpp b/game/server/baseanimating.cpp
index 5b3d3a11c4..d8b784147f 100644
--- a/game/server/baseanimating.cpp
+++ b/game/server/baseanimating.cpp
@@ -14,6 +14,8 @@
 #include "enginecallback.h"
 #include "entitylist_base.h"
 #include "mathlib/vector.h"
+#include "mathlib/vmatrix.h"
+#include "player.h"
 #include "shareddefs.h"
 #include "studio.h"
 #include "bone_setup.h"
@@ -289,6 +291,8 @@ CBaseAnimating::CBaseAnimating()
 	m_fadeMaxDist = 0;
 	m_flFadeScale = 0.0f;
 	m_fBoneCacheFlags = 0;
+    m_pBoneMergeCache    = NULL;
+    m_pBoneCache = NULL;
 }
 
 CBaseAnimating::~CBaseAnimating()
@@ -1693,6 +1697,32 @@ void CBaseAnimating::Teleport( const Vector *newPosition, const QAngle *newAngle
 }
 
 
+void CBaseAnimating::GetPoseParameters( CStudioHdr *pStudioHdr, float poseParameter[MAXSTUDIOPOSEPARAM])
+{
+	if ( !pStudioHdr )
+		return;
+
+	// interpolate pose parameters
+	int i;
+	for( i=0; i < pStudioHdr->GetNumPoseParameters(); i++)
+	{
+		poseParameter[i] = m_flPoseParameter[i];
+	}
+}
+
+void CBaseAnimating::GetEncodedControllers(CStudioHdr* pStudioHdr, float encodedControllers[MAXSTUDIOBONECTRLS])
+{
+	if ( !pStudioHdr )
+		return;
+
+  	// interpolate pose parameters
+	int i;
+	for( i=0; i < pStudioHdr->GetNumPoseParameters(); i++)
+	{
+		encodedControllers[i] = m_flEncodedController[i];
+	}  
+}
+
 //-----------------------------------------------------------------------------
 // Purpose: build matrices first from the parent, then from the passed in arrays if the bone doesn't exist on the parent
 //-----------------------------------------------------------------------------
@@ -1704,45 +1734,56 @@ void CBaseAnimating::BuildMatricesWithBoneMerge(
 	const Vector pos[MAXSTUDIOBONES],
 	const Quaternion q[MAXSTUDIOBONES],
 	matrix3x4_t bonetoworld[MAXSTUDIOBONES],
-	CBaseAnimating *pParent,
-	CBoneCache *pParentCache
+	int boneMask
 	)
 {
-	CStudioHdr *fhdr = pParent->GetModelPtr();
 	mstudiobone_t *pbones = pStudioHdr->pBone( 0 );
 
 	matrix3x4_t rotationmatrix; // model to world transformation
 	AngleMatrix( angles, origin, rotationmatrix);
 
-	for ( int i=0; i < pStudioHdr->numbones(); i++ )
+    bool boneMerge = IsEffectActive(EF_BONEMERGE);
+	if ( boneMerge || m_pBoneMergeCache )
 	{
-		// Now find the bone in the parent entity.
-		bool merged = false;
-		int parentBoneIndex = Studio_BoneIndexByName( fhdr, pbones[i].pszName() );
-		if ( parentBoneIndex >= 0 )
+		if ( boneMerge )
 		{
-			matrix3x4_t *pMat = pParentCache->GetCachedBone( parentBoneIndex );
-			if ( pMat )
+			if ( !m_pBoneMergeCache )
 			{
-				MatrixCopy( *pMat, bonetoworld[ i ] );
-				merged = true;
+				m_pBoneMergeCache = new CBoneMergeCache;
+				m_pBoneMergeCache->Init( this );
 			}
+			m_pBoneMergeCache->MergeMatchingBones( boneMask, bonetoworld );
 		}
-
-		if ( !merged )
+		else
 		{
-			// If we get down here, then the bone wasn't merged.
-			matrix3x4_t bonematrix;
-			QuaternionMatrix( q[i], pos[i], bonematrix );
+			delete m_pBoneMergeCache;
+			m_pBoneMergeCache = NULL;
+		}
+	}
+            
+	for ( int i=0; i < pStudioHdr->numbones(); i++ )
+    {
+        if (!(pStudioHdr->boneFlags(i) & boneMask))
+        {
+            continue;
+        }
+        
+        if (m_pBoneMergeCache && m_pBoneMergeCache->IsBoneMerged(i))
+        {
+            continue;
+        }
 
-			if (pbones[i].parent == -1) 
-			{
-				ConcatTransforms (rotationmatrix, bonematrix, bonetoworld[i]);
-			} 
-			else 
-			{
-				ConcatTransforms (bonetoworld[pbones[i].parent], bonematrix, bonetoworld[i]);
-			}
+        // If we get down here, then the bone wasn't merged.
+		matrix3x4_t bonematrix;
+		QuaternionMatrix( q[i], pos[i], bonematrix );
+
+		if (pbones[i].parent == -1) 
+		{
+			ConcatTransforms (rotationmatrix, bonematrix, bonetoworld[i]);
+		} 
+		else 
+		{
+			ConcatTransforms (bonetoworld[pbones[i].parent], bonematrix, bonetoworld[i]);
 		}
 	}
 }
@@ -1772,24 +1813,56 @@ inline bool CBaseAnimating::CanSkipAnimation( void )
 }
 
 
-void CBaseAnimating::SetupBones( matrix3x4_t *pBoneToWorld, int boneMask )
+void CBaseAnimating::SetupBones( CStudioHdr* pStudioHdr, matrix3x4_t *pBoneToWorld, int boneMask )
 {
+    static constexpr auto flDebugDuration = 60.f;
 	AUTO_LOCK( m_BoneSetupMutex );
 	
 	VPROF_BUDGET( "CBaseAnimating::SetupBones", VPROF_BUDGETGROUP_SERVER_ANIM );
 	
 	MDLCACHE_CRITICAL_SECTION();
 
-	Assert( GetModelPtr() );
+    m_pBoneCache = Studio_GetBoneCache(m_boneCacheHandle);
 
-	CStudioHdr *pStudioHdr = GetModelPtr( );
+	if ( m_pBoneCache )
+	{
+		if ( m_pBoneCache->IsValid( gpGlobals->curtime ) && (m_pBoneCache->m_boneMask & boneMask) == boneMask && m_pBoneCache->m_timeValid <= gpGlobals->curtime)
+		{
+			// Msg("%s:%s:%s (%x:%x:%8.4f) cache\n", GetClassname(), GetDebugName(), STRING(GetModelName()), boneMask, pcache->m_boneMask, pcache->m_timeValid );
+			// in memory and still valid, use it!
+            m_pBoneCache->ReadCachedBones(pBoneToWorld);
+            return;
+        }
+
+		// in memory, but missing some of the bone masks
+		if ( (m_pBoneCache->m_boneMask & boneMask) != boneMask )
+		{
+			Studio_DestroyBoneCache( m_boneCacheHandle );
+			m_boneCacheHandle = 0;
+			m_pBoneCache = NULL;
+		}
+    }
+    
+	if ( !m_pBoneCache )
+	{
+		bonecacheparams_t params;
+		params.pStudioHdr   = pStudioHdr;
+		params.pBoneToWorld = pBoneToWorld;
+		params.curtime      = gpGlobals->curtime;
+		params.boneMask     = boneMask;
+
+		m_boneCacheHandle = Studio_CreateBoneCache(params);
+		m_pBoneCache      = Studio_GetBoneCache(m_boneCacheHandle);
+    }
+
+	Assert( pStudioHdr );
 
 	if(!pStudioHdr)
 	{
 		Assert(!"CBaseAnimating::GetSkeleton() without a model");
 		return;
 	}
-
+   
 	Assert( !IsEFlagSet( EFL_SETTING_UP_BONES ) );
 
 	AddEFlags( EFL_SETTING_UP_BONES );
@@ -1797,8 +1870,8 @@ void CBaseAnimating::SetupBones( matrix3x4_t *pBoneToWorld, int boneMask )
 	Vector pos[MAXSTUDIOBONES];
 	Quaternion q[MAXSTUDIOBONES];
 
-	// adjust hit boxes based on IK driven offset
-	Vector adjOrigin = GetAbsOrigin() + Vector( 0, 0, m_flEstIkOffset );
+	// Remove IK to respect more the client hitboxes.
+	Vector adjOrigin = GetAbsOrigin();
 
 	if ( CanSkipAnimation() )
 	{
@@ -1825,49 +1898,16 @@ void CBaseAnimating::SetupBones( matrix3x4_t *pBoneToWorld, int boneMask )
 			// Msg( "%.03f : %s:%s\n", gpGlobals->curtime, GetClassname(), GetEntityName().ToCStr() );
 			GetSkeleton( pStudioHdr, pos, q, boneMask );
 		}
-	}
-	
-	CBaseAnimating *pParent = dynamic_cast< CBaseAnimating* >( GetMoveParent() );
-	if ( pParent )
-	{
-		// We're doing bone merging, so do special stuff here.
-		CBoneCache *pParentCache = pParent->GetBoneCache();
-		if ( pParentCache )
-		{
-			BuildMatricesWithBoneMerge( 
-				pStudioHdr, 
-				GetAbsAngles(), 
-				adjOrigin, 
-				pos, 
-				q, 
-				pBoneToWorld, 
-				pParent, 
-				pParentCache );
-			
-			RemoveEFlags( EFL_SETTING_UP_BONES );
-			if (ai_setupbones_debug.GetBool())
-			{
-				DrawRawSkeleton( pBoneToWorld, boneMask, true, 0.11 );
-			}
-			return;
-		}
-	}
+    }
 
-	Studio_BuildMatrices( 
-		pStudioHdr, 
-		GetAbsAngles(), 
-		adjOrigin, 
-		pos, 
-		q, 
-		-1,
-		GetModelScale(), // Scaling
-		pBoneToWorld,
-		boneMask );
+    BuildMatricesWithBoneMerge(pStudioHdr, GetAbsAngles(), adjOrigin, pos, q, pBoneToWorld, boneMask);
+
+    m_pBoneCache->UpdateBones(pBoneToWorld,  pStudioHdr->numbones(), gpGlobals->curtime);
 
 	if (ai_setupbones_debug.GetBool())
 	{
 		// Msg("%s:%s:%s (%x)\n", GetClassname(), GetDebugName(), STRING(GetModelName()), boneMask );
-		DrawRawSkeleton( pBoneToWorld, boneMask, true, 0.11 );
+		DrawRawSkeleton( pBoneToWorld, boneMask, true, flDebugDuration );
 	}
 	RemoveEFlags( EFL_SETTING_UP_BONES );
 }
@@ -2588,51 +2628,33 @@ CBoneCache *CBaseAnimating::GetBoneCache( void )
 	CStudioHdr *pStudioHdr = GetModelPtr( );
 	Assert(pStudioHdr);
 
-	CBoneCache *pcache = Studio_GetBoneCache( m_boneCacheHandle );
-	int boneMask = BONE_USED_BY_HITBOX | BONE_USED_BY_ATTACHMENT;
+	int boneMask = BONE_USED_BY_HITBOX | BONE_USED_BY_ATTACHMENT | BONE_USED_BY_BONE_MERGE;
 
 	// TF queries these bones to position weapons when players are killed
 #if defined( TF_DLL )
 	boneMask |= BONE_USED_BY_BONE_MERGE;
 #endif
-	if ( pcache )
-	{
-		if ( pcache->IsValid( gpGlobals->curtime ) && (pcache->m_boneMask & boneMask) == boneMask && pcache->m_timeValid <= gpGlobals->curtime)
-		{
-			// Msg("%s:%s:%s (%x:%x:%8.4f) cache\n", GetClassname(), GetDebugName(), STRING(GetModelName()), boneMask, pcache->m_boneMask, pcache->m_timeValid );
-			// in memory and still valid, use it!
-			return pcache;
-		}
-		// in memory, but missing some of the bone masks
-		if ( (pcache->m_boneMask & boneMask) != boneMask )
-		{
-			Studio_DestroyBoneCache( m_boneCacheHandle );
-			m_boneCacheHandle = 0;
-			pcache = NULL;
-		}
-	}
 
 	matrix3x4_t bonetoworld[MAXSTUDIOBONES];
-	SetupBones( bonetoworld, boneMask );
+	SetupBones( GetModelPtr(), bonetoworld, boneMask );
 
-	if ( pcache )
-	{
-		// still in memory but out of date, refresh the bones.
-		pcache->UpdateBones( bonetoworld, pStudioHdr->numbones(), gpGlobals->curtime );
-	}
-	else
-	{
-		bonecacheparams_t params;
-		params.pStudioHdr = pStudioHdr;
-		params.pBoneToWorld = bonetoworld;
-		params.curtime = gpGlobals->curtime;
-		params.boneMask = boneMask;
+    for (auto pChild = FirstMoveChild(); pChild; pChild = pChild->NextMovePeer())
+    {
+        auto pChildAnimating = dynamic_cast<CBaseAnimating*>(pChild);
 
-		m_boneCacheHandle = Studio_CreateBoneCache( params );
-		pcache = Studio_GetBoneCache( m_boneCacheHandle );
-	}
-	Assert(pcache);
-	return pcache;
+        if (!pChildAnimating || !pChildAnimating->GetModelPtr())
+        {
+            continue;
+        }
+
+        printf("animating: %i %s %s\n", pChildAnimating->entindex(), pChildAnimating->GetDebugName(), pChildAnimating->GetModelName().ToCStr());
+
+        matrix3x4_t childbones[MAXSTUDIOBONES];
+        pChildAnimating->SetupBones(pChildAnimating->GetModelPtr(), childbones, boneMask);
+    }
+
+	Assert(m_pBoneCache);
+	return m_pBoneCache;
 }
 
 
@@ -2810,7 +2832,12 @@ void CBaseAnimating::GetSkeleton( CStudioHdr *pStudioHdr, Vector pos[], Quaterni
 		return;
 	}
 
-	IBoneSetup boneSetup( pStudioHdr, boneMask, GetPoseParameterArray() );
+    float flPoseParams[MAXSTUDIOPOSEPARAM];
+    float flEncodedParams[MAXSTUDIOBONECTRLS];
+
+    GetPoseParameters( pStudioHdr, flPoseParams );
+
+	IBoneSetup boneSetup( pStudioHdr, boneMask, flPoseParams );
 	boneSetup.InitPose( pos, q );
 
 	boneSetup.AccumulatePose( pos, q, GetSequence(), GetCycle(), 1.0, gpGlobals->curtime, m_pIk );
@@ -2825,7 +2852,8 @@ void CBaseAnimating::GetSkeleton( CStudioHdr *pStudioHdr, Vector pos[], Quaterni
 	{
 		boneSetup.CalcAutoplaySequences( pos, q, gpGlobals->curtime, NULL );
 	}
-	boneSetup.CalcBoneAdj( pos, q, GetEncodedControllerArray() );
+    GetEncodedControllers( pStudioHdr, flEncodedParams );
+	boneSetup.CalcBoneAdj( pos, q, flEncodedParams );
 }
 
 int CBaseAnimating::DrawDebugTextOverlays(void) 
@@ -3067,8 +3095,14 @@ void CBaseAnimating::DrawRawSkeleton( matrix3x4_t boneToWorld[], int boneMask, b
 	int i;
 	int r = 255;
 	int g = 255;
-	int b = monocolor ? 255 : 0;
-	
+    int b = monocolor ? 255 : 0;
+
+    if (boneMask & 0x00080000)
+    {
+        r = 0;
+        g = 0;
+        b = 255;
+	}
 
 	for (i = 0; i < pStudioHdr->numbones(); i++)
 	{
@@ -3080,6 +3114,14 @@ void CBaseAnimating::DrawRawSkeleton( matrix3x4_t boneToWorld[], int boneMask, b
 			{
 				Vector p2;
 				MatrixPosition( boneToWorld[pStudioHdr->pBone( i )->parent], p2 );
+                if (pStudioHdr->pBone(i)->flags & BONE_USED_BY_BONE_MERGE)
+                {
+                    r = 255;
+                }
+                else
+                {
+                    r = 0;
+                }
                 NDebugOverlay::Line( p1, p2, r, g, b, noDepthTest, duration );
 			}
 		}
@@ -3605,6 +3647,12 @@ CStudioHdr *CBaseAnimating::OnNewModel()
 {
 	(void) BaseClass::OnNewModel();
 
+    if ( m_pBoneMergeCache )
+	{
+		delete m_pBoneMergeCache;
+		m_pBoneMergeCache = NULL;
+    }
+
 	// TODO: if dynamic, validate m_Sequence and apply queued body group settings?
 	if ( IsDynamicModelLoading() )
 	{
diff --git a/game/server/baseanimating.h b/game/server/baseanimating.h
index d96d01e697..666dcf5590 100644
--- a/game/server/baseanimating.h
+++ b/game/server/baseanimating.h
@@ -18,6 +18,7 @@
 #include "studio.h"
 #include "datacache/idatacache.h"
 #include "tier0/threadtools.h"
+#include "bone_merge_cache.h"
 
 class CBasePlayer;
 struct animevent_t;
@@ -136,7 +137,7 @@ public:
 	virtual	void GetSkeleton( CStudioHdr *pStudioHdr, Vector pos[], Quaternion q[], int boneMask );
 
 	virtual void GetBoneTransform( int iBone, matrix3x4_t &pBoneToWorld );
-	virtual void SetupBones( matrix3x4_t *pBoneToWorld, int boneMask );
+	virtual void SetupBones( CStudioHdr *pStudioHdr, matrix3x4_t *pBoneToWorld, int boneMask );
 	virtual void CalculateIKLocks( float currentTime );
 	virtual void Teleport( const Vector *newPosition, const QAngle *newAngles, const Vector *newVelocity );
 
@@ -160,7 +161,8 @@ public:
 	bool	HasPoseParameter( int iSequence, const char *szName );
 	bool	HasPoseParameter( int iSequence, int iParameter );
 	float	EdgeLimitPoseParameter( int iParameter, float flValue, float flBase = 0.0f );
-
+    virtual void GetPoseParameters(CStudioHdr* pStudioHdr, float poseParameter[MAXSTUDIOPOSEPARAM]);
+    virtual void GetEncodedControllers(CStudioHdr* pStudioHdr, float encodedControllers[MAXSTUDIOBONECTRLS]);
 protected:
 	// The modus operandi for pose parameters is that you should not use the const char * version of the functions
 	// in general code -- it causes many many string comparisons, which is slower than you think. Better is to 
@@ -326,8 +328,7 @@ public:
 
 	void BuildMatricesWithBoneMerge( const CStudioHdr *pStudioHdr, const QAngle& angles, 
 		const Vector& origin, const Vector pos[MAXSTUDIOBONES],
-		const Quaternion q[MAXSTUDIOBONES], matrix3x4_t bonetoworld[MAXSTUDIOBONES],
-		CBaseAnimating *pParent, CBoneCache *pParentCache );
+		const Quaternion q[MAXSTUDIOBONES], matrix3x4_t bonetoworld[MAXSTUDIOBONES], int boneMask );
 
 	void	SetFadeDistance( float minFadeDist, float maxFadeDist );
 
@@ -336,10 +337,10 @@ public:
 	inline void	ClearBoneCacheFlags( unsigned short fFlag ) { m_fBoneCacheFlags &= ~fFlag; }
 
 	bool PrefetchSequence( int iSequence );
+	virtual void LockStudioHdr();
+	virtual void UnlockStudioHdr();
 
 private:
-	void LockStudioHdr();
-	void UnlockStudioHdr();
 
 	void StudioFrameAdvanceInternal( CStudioHdr *pStudioHdr, float flInterval );
 	void InputSetLightingOriginRelative( inputdata_t &inputdata );
@@ -422,10 +423,12 @@ protected:
 public:
 	COutputEvent m_OnIgnite;
 
-private:
+public:
 	CStudioHdr			*m_pStudioHdr;
 	CThreadFastMutex	m_StudioHdrInitLock;
 	CThreadFastMutex	m_BoneSetupMutex;
+	CBoneCache          *m_pBoneCache;
+	CBoneMergeCache     *m_pBoneMergeCache;
 
 // FIXME: necessary so that cyclers can hack m_bSequenceFinished
 friend class CFlexCycler;
diff --git a/game/server/hl2/npc_barnacle.cpp b/game/server/hl2/npc_barnacle.cpp
index 9e82435180..72566bcf76 100644
--- a/game/server/hl2/npc_barnacle.cpp
+++ b/game/server/hl2/npc_barnacle.cpp
@@ -1100,13 +1100,13 @@ void CNPC_Barnacle::LiftRagdoll( float flBiteZOffset )
 
 			// Get the current bone matrix
 			matrix3x4_t pBoneToWorld[MAXSTUDIOBONES];
-			pAnimating->SetupBones( pBoneToWorld, BONE_USED_BY_ANYTHING );
+			pAnimating->SetupBones( pAnimating->GetModelPtr(), pBoneToWorld, BONE_USED_BY_ANYTHING );
 
 			// Apply the forces to the ragdoll
 			RagdollApplyAnimationAsVelocity( *(m_hRagdoll->GetRagdoll()), m_pRagdollBones, pBoneToWorld, 0.2 );
 
 			// Store off the current bone matrix for next time
-			pAnimating->SetupBones( m_pRagdollBones, BONE_USED_BY_ANYTHING );
+			pAnimating->SetupBones( pAnimating->GetModelPtr(), m_pRagdollBones, BONE_USED_BY_ANYTHING );
 		}
 	}
 }
@@ -1540,7 +1540,7 @@ You can use this stanza to try to counterplace the constraint on the player's he
 	UpdateTongue();
 
 	// Store off the current bone matrix so we have it next frame
-	pAnimating->SetupBones( m_pRagdollBones, BONE_USED_BY_ANYTHING );
+	pAnimating->SetupBones( pAnimating->GetModelPtr(), m_pRagdollBones, BONE_USED_BY_ANYTHING );
 }
 
 
diff --git a/game/server/physics_prop_ragdoll.cpp b/game/server/physics_prop_ragdoll.cpp
index 72635ea897..5e83ae57f3 100644
--- a/game/server/physics_prop_ragdoll.cpp
+++ b/game/server/physics_prop_ragdoll.cpp
@@ -174,7 +174,7 @@ void CRagdollProp::Spawn( void )
 	}
 
 	matrix3x4_t pBoneToWorld[MAXSTUDIOBONES];
-	BaseClass::SetupBones( pBoneToWorld, BONE_USED_BY_ANYTHING ); // FIXME: shouldn't this be a subset of the bones
+	BaseClass::SetupBones( GetModelPtr(), pBoneToWorld, BONE_USED_BY_ANYTHING ); // FIXME: shouldn't this be a subset of the bones
 	// this is useless info after the initial conditions are set
 	SetAbsAngles( vec3_angle );
 	int collisionGroup = (m_spawnflags & SF_RAGDOLLPROP_DEBRIS) ? COLLISION_GROUP_DEBRIS : COLLISION_GROUP_NONE;
@@ -827,7 +827,7 @@ void CRagdollProp::SetupBones( matrix3x4_t *pBoneToWorld, int boneMask )
 	// no ragdoll, fall through to base class 
 	if ( !m_ragdoll.listCount )
 	{
-		BaseClass::SetupBones( pBoneToWorld, boneMask );
+		BaseClass::SetupBones( GetModelPtr(), pBoneToWorld, boneMask );
 		return;
 	}
 
@@ -1338,10 +1338,10 @@ CBaseEntity *CreateServerRagdoll( CBaseAnimating *pAnimating, int forceBone, con
 	float fPreviousCycle = clamp(pAnimating->GetCycle()-( dt * ( 1 / fSequenceDuration ) ),0.f,1.f);
 	float fCurCycle = pAnimating->GetCycle();
 	// Get current bones positions
-	pAnimating->SetupBones( pBoneToWorldNext, BONE_USED_BY_ANYTHING );
+	pAnimating->SetupBones( pAnimating->GetModelPtr(), pBoneToWorldNext, BONE_USED_BY_ANYTHING );
 	// Get previous bones positions
 	pAnimating->SetCycle( fPreviousCycle );
-	pAnimating->SetupBones( pBoneToWorld, BONE_USED_BY_ANYTHING );		
+	pAnimating->SetupBones( pAnimating->GetModelPtr(), pBoneToWorld, BONE_USED_BY_ANYTHING );		
 	// Restore current cycle
 	pAnimating->SetCycle( fCurCycle );
 
@@ -1579,7 +1579,7 @@ CRagdollProp *CreateServerRagdollAttached( CBaseAnimating *pAnimating, const Vec
 
 	pRagdoll->InitRagdollAnimation();
 	matrix3x4_t pBoneToWorld[MAXSTUDIOBONES];
-	pAnimating->SetupBones( pBoneToWorld, BONE_USED_BY_ANYTHING );
+	pAnimating->SetupBones( pAnimating->GetModelPtr(), pBoneToWorld, BONE_USED_BY_ANYTHING );
 	pRagdoll->InitRagdollAttached( pAttached, vecForce, forceBone, pBoneToWorld, pBoneToWorld, 0.1, collisionGroup, pParentEntity, boneAttach, boneOrigin, parentBoneAttach, originAttached );
 	
 	return pRagdoll;
diff --git a/game/server/player_lagcompensation.cpp b/game/server/player_lagcompensation.cpp
index 9d43980cc1..52d269bed0 100644
--- a/game/server/player_lagcompensation.cpp
+++ b/game/server/player_lagcompensation.cpp
@@ -32,7 +32,7 @@
 
 ConVar sv_unlag( "sv_unlag", "1", FCVAR_DEVELOPMENTONLY, "Enables player lag compensation" );
 ConVar sv_maxunlag( "sv_maxunlag", "1.0", FCVAR_DEVELOPMENTONLY, "Maximum lag compensation in seconds", true, 0.0f, true, 1.0f );
-ConVar sv_lagflushbonecache( "sv_lagflushbonecache", "1", FCVAR_DEVELOPMENTONLY, "Flushes entity bone cache on lag compensation" );
+ConVar sv_lagflushbonecache( "sv_lagflushbonecache", "0", FCVAR_DEVELOPMENTONLY, "Flushes entity bone cache on lag compensation" );
 ConVar sv_unlag_fixstuck( "sv_unlag_fixstuck", "0", FCVAR_DEVELOPMENTONLY, "Disallow backtracking a player for lag compensation if it will cause them to become stuck" );
 
 //-----------------------------------------------------------------------------
diff --git a/game/server/server_base.vpc b/game/server/server_base.vpc
index 6d78d55dc8..cfa14816be 100644
--- a/game/server/server_base.vpc
+++ b/game/server/server_base.vpc
@@ -78,6 +78,7 @@ $Project
 	
 	$Folder	"Source Files"
 	{
+		$File	"$SRCDIR\game\shared\bone_merge_cache.cpp"
 		$File	"$SRCDIR\game\shared\achievement_saverestore.cpp"
 		$File	"$SRCDIR\game\shared\achievement_saverestore.h"
 		$File	"$SRCDIR\game\shared\achievementmgr.cpp"
@@ -785,6 +786,7 @@ $Project
 
 	$Folder	"Header Files"
 	{
+		$File	"$SRCDIR\game\shared\bone_merge_cache.h"
 		$File	"$SRCDIR\public\mathlib\amd3dx.h"
 		$File	"$SRCDIR\game\shared\ammodef.h"
 		$File	"$SRCDIR\game\shared\base_playeranimstate.h"
diff --git a/game/shared/basecombatweapon_shared.cpp b/game/shared/basecombatweapon_shared.cpp
index 0b35d14700..bafbbaa938 100644
--- a/game/shared/basecombatweapon_shared.cpp
+++ b/game/shared/basecombatweapon_shared.cpp
@@ -15,6 +15,8 @@
 
 // NVNT start extra includes
 #include "haptics/haptic_utils.h"
+#include "studio.h"
+#include "tier3/tier3.h"
 #ifdef CLIENT_DLL
 	#include "prediction.h"
 #endif
@@ -90,6 +92,7 @@ CBaseCombatWeapon::CBaseCombatWeapon() : BASECOMBATWEAPON_DERIVED_FROM()
 #if !defined( CLIENT_DLL )
 	m_pConstraint = NULL;
 	OnBaseCombatWeaponCreated( this );
+    m_pStudioWorldHdr = NULL;
 #endif
 
 	m_hWeaponFileInfo = GetInvalidWeaponInfoHandle();
@@ -117,10 +120,76 @@ CBaseCombatWeapon::~CBaseCombatWeapon( void )
 		physenv->DestroyConstraint( m_pConstraint );
 		m_pConstraint = NULL;
 	}
-	OnBaseCombatWeaponDestroyed( this );
+    OnBaseCombatWeaponDestroyed(this);
+    delete m_pStudioWorldHdr;
 #endif
 }
 
+#ifndef CLIENT_DLL
+void CBaseCombatWeapon::LockStudioHdr()
+{
+    BaseClass::LockStudioHdr();
+
+	AUTO_LOCK( m_StudioHdrInitLock );
+    const auto worldModel = modelinfo->GetModel(m_iWorldModelIndex);
+	if (worldModel)
+	{
+		MDLHandle_t hStudioHdr = modelinfo->GetCacheHandle( worldModel );
+		if ( hStudioHdr != MDLHANDLE_INVALID )
+		{
+			const studiohdr_t *pStudioHdr = mdlcache->LockStudioHdr( hStudioHdr );
+			CStudioHdr *pStudioHdrContainer = NULL;
+			if ( !m_pStudioWorldHdr )
+			{
+				if ( pStudioHdr )
+				{
+					pStudioHdrContainer = new CStudioHdr;
+					pStudioHdrContainer->Init( pStudioHdr, mdlcache );
+				}
+			}
+			else
+			{
+				pStudioHdrContainer = m_pStudioWorldHdr;
+			}
+
+			Assert( ( pStudioHdr == NULL && pStudioHdrContainer == NULL ) || pStudioHdrContainer->GetRenderHdr() == pStudioHdr );
+
+			if ( pStudioHdrContainer && pStudioHdrContainer->GetVirtualModel() )
+			{
+				MDLHandle_t hVirtualModel = VoidPtrToMDLHandle( pStudioHdrContainer->GetRenderHdr()->VirtualModel() );
+				mdlcache->LockStudioHdr( hVirtualModel );
+			}
+			m_pStudioWorldHdr = pStudioHdrContainer; // must be last to ensure virtual model correctly set up
+		}
+	}
+}
+
+void CBaseCombatWeapon::UnlockStudioHdr()
+{
+    BaseClass::UnlockStudioHdr();
+
+	if ( m_pStudioWorldHdr )
+	{
+    	const auto worldModel = modelinfo->GetModel(m_iWorldModelIndex);
+		if (worldModel)
+		{
+			mdlcache->UnlockStudioHdr( modelinfo->GetCacheHandle( worldModel ) );
+			if ( m_pStudioWorldHdr->GetVirtualModel() )
+			{
+				MDLHandle_t hVirtualModel = VoidPtrToMDLHandle( m_pStudioWorldHdr->GetRenderHdr()->VirtualModel() );
+				mdlcache->UnlockStudioHdr( hVirtualModel );
+			}
+        }
+    }
+}
+
+void CBaseCombatWeapon::SetupBones(CStudioHdr* pStudioHdr, matrix3x4_t* pBoneToWorld, int boneMask)
+{
+    // hooked m_pStudioHdr to world model instead (m_pStudioWorldHdr)
+    BaseClass::SetupBones(m_pStudioWorldHdr, pBoneToWorld, boneMask);
+}
+#endif
+
 void CBaseCombatWeapon::Activate( void )
 {
 	BaseClass::Activate();
diff --git a/game/shared/basecombatweapon_shared.h b/game/shared/basecombatweapon_shared.h
index 701403a07f..3dc95ea97a 100644
--- a/game/shared/basecombatweapon_shared.h
+++ b/game/shared/basecombatweapon_shared.h
@@ -6,6 +6,7 @@
 
 #ifndef COMBATWEAPON_SHARED_H
 #define COMBATWEAPON_SHARED_H
+#include "studio.h"
 #ifdef _WIN32
 #pragma once
 #endif
@@ -162,7 +163,11 @@ public:
 
 							CBaseCombatWeapon();
 	virtual 				~CBaseCombatWeapon();
-
+#ifndef CLIENT_DLL
+	virtual void LockStudioHdr();
+	virtual void UnlockStudioHdr();
+	virtual void SetupBones( CStudioHdr* pStudioHdr, matrix3x4_t *pBoneToWorld, int boneMask );
+#endif
 	virtual bool			IsBaseCombatWeapon( void ) const { return true; }
 	virtual CBaseCombatWeapon *MyCombatWeaponPointer( void ) { return this; }
 
@@ -612,9 +617,9 @@ private:
 	bool					m_bReloadHudHintDisplayed;	// Have we displayed a reload HUD hint since this weapon was deployed?
 	float					m_flHudHintPollTime;	// When to poll the weapon again for whether it should display a hud hint.
 	float					m_flHudHintMinDisplayTime; // if the hint is squelched before this, reset my counter so we'll display it again.
-	
 	// Server only
 #if !defined( CLIENT_DLL )
+	CStudioHdr             *m_pStudioWorldHdr;
 
 	// Outputs
 protected:
diff --git a/game/client/bone_merge_cache.cpp b/game/shared/bone_merge_cache.cpp
similarity index 72%
rename from game/client/bone_merge_cache.cpp
rename to game/shared/bone_merge_cache.cpp
index 6ef767eadc..1138604b6b 100644
--- a/game/client/bone_merge_cache.cpp
+++ b/game/shared/bone_merge_cache.cpp
@@ -11,6 +11,8 @@
 #include "bone_setup.h"
 
 // memdbgon must be the last include file in a .cpp file!!!
+#include "mathlib/mathlib.h"
+#include "studio.h"
 #include "tier0/memdbgon.h"
 
 //-----------------------------------------------------------------------------
@@ -27,7 +29,7 @@ CBoneMergeCache::CBoneMergeCache()
 	m_nFollowBoneSetupMask = 0;
 }
 
-void CBoneMergeCache::Init( C_BaseAnimating *pOwner )
+void CBoneMergeCache::Init( CBaseAnimating *pOwner )
 {
 	m_pOwner = pOwner;
 	m_pFollow = NULL;
@@ -40,7 +42,7 @@ void CBoneMergeCache::Init( C_BaseAnimating *pOwner )
 void CBoneMergeCache::UpdateCache()
 {
 	CStudioHdr *pOwnerHdr = m_pOwner ? m_pOwner->GetModelPtr() : NULL;
-	if ( !pOwnerHdr )
+	if ( !pOwnerHdr || !m_pOwner->GetFollowedEntity())
 	{
 		if ( m_pOwnerHdr )
 		{
@@ -56,7 +58,11 @@ void CBoneMergeCache::UpdateCache()
 		return;
 	}
 
-	C_BaseAnimating *pTestFollow = m_pOwner->FindFollowedEntity();
+#ifdef CLIENT_DLL
+    C_BaseAnimating* pTestFollow = m_pOwner->FindFollowedEntity();
+#else
+    CBaseAnimating* pTestFollow = dynamic_cast<CBaseAnimating*>(m_pOwner->GetFollowedEntity());
+#endif
 	CStudioHdr *pTestHdr = (pTestFollow ? pTestFollow->GetModelPtr() : NULL);
 	const studiohdr_t *pTestStudioHDR = (pTestHdr ? pTestHdr->GetRenderHdr() : NULL);
 	if ( pTestFollow != m_pFollow || pTestHdr != m_pFollowHdr || pTestStudioHDR != m_pFollowRenderHdr || pOwnerHdr != m_pOwnerHdr )
@@ -83,7 +89,9 @@ void CBoneMergeCache::UpdateCache()
 				int parentBoneIndex = Studio_BoneIndexByName( m_pFollowHdr, pOwnerBones[i].pszName() );
 				if ( parentBoneIndex < 0 )
 					continue;
-
+#ifdef CLIENT_DLL
+                printf("bone attach: (%i - %i) (%s - %s) (%s - %s)\n", m_pFollow->entindex(), m_pOwner->entindex(), m_pFollow->GetDebugName(), m_pOwner->GetDebugName(), m_pFollow->GetModelName(), m_pOwner->GetModelName());
+#endif
 				// Add a merged bone here.
 				CMergedBone mergedBone;
 				mergedBone.m_iMyBone = i;
@@ -122,7 +130,7 @@ void CBoneMergeCache::UpdateCache()
 ConVar r_captain_canteen_is_angry ( "r_captain_canteen_is_angry", "1" );
 #endif
 
-void CBoneMergeCache::MergeMatchingBones( int boneMask )
+void CBoneMergeCache::MergeMatchingBones( int boneMask , matrix3x4_t mergedbones[MAXSTUDIOBONES] )
 {
 	UpdateCache();
 
@@ -130,55 +138,29 @@ void CBoneMergeCache::MergeMatchingBones( int boneMask )
 	if ( !m_pOwnerHdr || m_MergedBones.Count() == 0 )
 		return;
 
-	// Have the entity we're following setup its bones.
-	bool bWorked = m_pFollow->SetupBones( NULL, -1, m_nFollowBoneSetupMask, gpGlobals->curtime );
-	// We suspect there's some cases where SetupBones couldn't do its thing, and then this causes Captain Canteen.
-	Assert ( bWorked );
-	if ( !bWorked )
-	{
-		// Usually this means your parent is invisible or gone or whatever.
-		// This routine has no way to tell its caller not to draw itself unfortunately.
-		// But we can shrink all the bones down to zero size.
-		// But it might still spawn particle systems? :-(
-		matrix3x4_t NewBone;
-		MatrixScaleByZero ( NewBone );
-		MatrixSetTranslation ( Vector ( 0.0f, 0.0f, 0.0f ), NewBone );
-#ifdef STAGING_ONLY
-		if ( r_captain_canteen_is_angry.GetBool() )
-		{
-			// We actually want to see when Captain Canteen happened, and make it really obvious that (a) he was here and (b) this code would have fixed him.
-			float HowAngry = 20.0f;		// Leon's getting larger!
-			MatrixSetColumn ( Vector ( HowAngry, 0.0f, 0.0f ), 0, NewBone );
-			MatrixSetColumn ( Vector ( 0.0f, HowAngry, 0.0f ), 1, NewBone );
-			MatrixSetColumn ( Vector ( 0.0f, 0.0f, HowAngry ), 2, NewBone );
-		}
+    matrix3x4_t bones[MAXSTUDIOBONES];
+    // Have the entity we're following setup its bones.
+#ifdef CLIENT_DLL
+    m_pFollow->SetupBones(bones, MAXSTUDIOBONES, m_nFollowBoneSetupMask, gpGlobals->curtime);
+#else
+    m_pFollow->SetupBones(m_pFollow->GetModelPtr(), bones, m_nFollowBoneSetupMask);
 #endif
 
-		for ( int i=0; i < m_MergedBones.Count(); i++ )
-		{
-			int iOwnerBone = m_MergedBones[i].m_iMyBone;
-		
-			// Only update bones reference by the bone mask.
-			if ( !( m_pOwnerHdr->boneFlags( iOwnerBone ) & boneMask ) )
-				continue;
-
-			m_pOwner->GetBoneForWrite( iOwnerBone ) = NewBone;
-		}
-	}
-	else
+	// Now copy the bone matrices.
+	for ( int i=0; i < m_MergedBones.Count(); i++ )
 	{
-		// Now copy the bone matrices.
-		for ( int i=0; i < m_MergedBones.Count(); i++ )
-		{
-			int iOwnerBone = m_MergedBones[i].m_iMyBone;
-			int iParentBone = m_MergedBones[i].m_iParentBone;
+		int iOwnerBone = m_MergedBones[i].m_iMyBone;
+		int iParentBone = m_MergedBones[i].m_iParentBone;
+	
+		// Only update bones reference by the bone mask.
+		if ( !( m_pOwnerHdr->boneFlags( iOwnerBone ) & boneMask ) )
+			continue;
 		
-			// Only update bones reference by the bone mask.
-			if ( !( m_pOwnerHdr->boneFlags( iOwnerBone ) & boneMask ) )
-				continue;
-
-			MatrixCopy( m_pFollow->GetBone( iParentBone ), m_pOwner->GetBoneForWrite( iOwnerBone ) );
-		}
+#ifdef CLIENT_DLL
+		MatrixCopy( bones[ iParentBone ], mergedbones[ iOwnerBone ] );
+#else
+        MatrixCopy( bones[ iParentBone ], mergedbones[ iOwnerBone ] );
+#endif
 	}
 }
 
@@ -255,8 +237,14 @@ bool CBoneMergeCache::GetAimEntOrigin( Vector *pAbsOrigin, QAngle *pAbsAngles )
 	// all over the place, then this won't get the right results.
 	
 	// Get mFollowBone.
-	m_pFollow->SetupBones( NULL, -1, m_nFollowBoneSetupMask, gpGlobals->curtime );
-	const matrix3x4_t &mFollowBone = m_pFollow->GetBone( m_MergedBones[0].m_iParentBone );
+    matrix3x4_t bones[MAXSTUDIOBONES];
+    // Have the entity we're following setup its bones.
+#ifdef CLIENT_DLL
+    m_pFollow->SetupBones(bones, MAXSTUDIOBONES, m_nFollowBoneSetupMask, gpGlobals->curtime);
+#else
+    m_pFollow->SetupBones(m_pFollow->GetModelPtr(), bones, m_nFollowBoneSetupMask);
+#endif
+	const matrix3x4_t &mFollowBone = bones[ m_MergedBones[0].m_iParentBone ];
 
 	// Get Inverse( mBoneLocal )
 	matrix3x4_t mBoneLocal, mBoneLocalInv;
@@ -280,8 +268,14 @@ bool CBoneMergeCache::GetRootBone( matrix3x4_t &rootBone )
 		return false;
 
 	// Get mFollowBone.
-	m_pFollow->SetupBones( NULL, -1, m_nFollowBoneSetupMask, gpGlobals->curtime );
-	rootBone = m_pFollow->GetBone( m_MergedBones[0].m_iParentBone );
+    matrix3x4_t bones[MAXSTUDIOBONES];
+    // Have the entity we're following setup its bones.
+#ifdef CLIENT_DLL
+    m_pFollow->SetupBones(bones, MAXSTUDIOBONES, m_nFollowBoneSetupMask, gpGlobals->curtime);
+#else
+    m_pFollow->SetupBones(m_pFollow->GetModelPtr(), bones, m_nFollowBoneSetupMask);
+#endif
+	rootBone = bones[ m_MergedBones[0].m_iParentBone ];
 	return true;
 }
 
diff --git a/game/client/bone_merge_cache.h b/game/shared/bone_merge_cache.h
similarity index 85%
rename from game/client/bone_merge_cache.h
rename to game/shared/bone_merge_cache.h
index 6123c9b4a8..16f47e941b 100644
--- a/game/client/bone_merge_cache.h
+++ b/game/shared/bone_merge_cache.h
@@ -6,12 +6,21 @@
 
 #ifndef BONE_MERGE_CACHE_H
 #define BONE_MERGE_CACHE_H
+#include "mathlib/mathlib.h"
+#include "studio.h"
 #ifdef _WIN32
 #pragma once
 #endif
 
-
+#ifdef CLIENT_DLL
 class C_BaseAnimating;
+#ifndef CBaseAnimating
+#define CBaseAnimating C_BaseAnimating
+#endif
+#else
+class CBaseAnimating;
+#endif
+
 class CStudioHdr;
 
 
@@ -24,14 +33,14 @@ public:
 
 	CBoneMergeCache();
 	
-	void Init( C_BaseAnimating *pOwner );
+	void Init( CBaseAnimating *pOwner );
 
 	// Updates the lookups that let it merge bones quickly.
 	void UpdateCache();
 	
 	// This copies the transform from all bones in the followed entity that have 
 	// names that match our bones.
-	void MergeMatchingBones( int boneMask );
+	void MergeMatchingBones( int boneMask, matrix3x4_t mergedbones[MAXSTUDIOBONES] );
 
 	// copy bones instead of matrices
 	void CopyParentToChild( const Vector parentPos[], const Quaternion parentQ[], Vector childPos[], Quaternion childQ[], int boneMask );
@@ -48,11 +57,11 @@ public:
 private:
 
 	// This is the entity that we're keeping the cache updated for.
-	C_BaseAnimating *m_pOwner;
+	CBaseAnimating *m_pOwner;
 
 	// All the cache data is based off these. When they change, the cache data is regenerated.
 	// These are either all valid pointers or all NULL.
-	C_BaseAnimating *m_pFollow;
+	CBaseAnimating *m_pFollow;
 	CStudioHdr		*m_pFollowHdr;
 	const studiohdr_t	*m_pFollowRenderHdr;
 	CStudioHdr		*m_pOwnerHdr;
diff --git a/public/bone_setup.h b/public/bone_setup.h
index dbe50db93d..39a23eb116 100644
--- a/public/bone_setup.h
+++ b/public/bone_setup.h
@@ -419,7 +419,7 @@ public:
 	float			m_timeValid;
 	int				m_boneMask;
 
-private:
+public:
 	matrix3x4_t		*BoneArray();
 	short			*StudioToCached();
 	short			*CachedToStudio();