Pre-transform bones with inverse bind instead of sending it to the shader

src/Core/OpenGL/CShaderGenerator.cpp

@@ -227,7 +227,6 @@ bool CShaderGenerator::CreateVertexShader(const CMaterial& rkMat)
         ShaderCode  << "layout(std140) uniform BoneTransformBlock\n"
                     << "{\n"
                     << "    mat4 BoneTransforms[100];\n"
-                    << "    mat4 InverseBindTransforms[100];\n"
                     << "};\n"
                     << "\n";
     }
@@ -260,11 +259,10 @@ bool CShaderGenerator::CreateVertexShader(const CMaterial& rkMat)
                     << "        \n"
                     << "        if (BoneIdx > 0)\n"
                     << "        {\n"
-                    << "            mat4 BoneSpaceTransform = InverseBindTransforms[BoneIdx] * BoneTransforms[BoneIdx];\n"
+                    << "            ModelSpacePos += vec3(vec4(RawPosition, 1) * BoneTransforms[BoneIdx] * Weight);\n";
-                    << "            ModelSpacePos += vec3(vec4(RawPosition, 1) * BoneSpaceTransform * Weight);\n";
 
         if (VtxDesc & eNormal)
-            ShaderCode  << "            ModelSpaceNormal += RawNormal.xyz * inverse(transpose(mat3(BoneSpaceTransform))) * Weight;\n";
+            ShaderCode  << "            ModelSpaceNormal += RawNormal.xyz * inverse(transpose(mat3(BoneTransforms[BoneIdx]))) * Weight;\n";
 
         ShaderCode  << "        }\n"
                     << "    }\n"

src/Core/Render/CGraphics.cpp

@@ -14,7 +14,6 @@ u32 CGraphics::mActiveContext = -1;
 bool CGraphics::mInitialized = false;
 std::vector<CVertexArrayManager*> CGraphics::mVAMs;
 bool CGraphics::mIdentityBoneTransforms = false;
-const CSkeleton *CGraphics::mpkCurrentSkeleton = nullptr;
 
 CGraphics::SMVPBlock    CGraphics::sMVPBlock;
 CGraphics::SVertexBlock CGraphics::sVertexBlock;
@@ -47,7 +46,7 @@ void CGraphics::Initialize()
         mpVertexBlockBuffer = new CUniformBuffer(sizeof(sVertexBlock));
         mpPixelBlockBuffer = new CUniformBuffer(sizeof(sPixelBlock));
         mpLightBlockBuffer = new CUniformBuffer(sizeof(sLightBlock));
-        mpBoneTransformBuffer = new CUniformBuffer(sizeof(CTransform4f) * 200);
+        mpBoneTransformBuffer = new CUniformBuffer(sizeof(CTransform4f) * 100);
 
         sLightMode = eWorldLighting;
         sNumLights = 0;
@@ -197,24 +196,13 @@ void CGraphics::LoadBoneTransforms(const CBoneTransformData& rkData)
     mIdentityBoneTransforms = false;
 }
 
-void CGraphics::LoadBoneInverseBindTransforms(CSkeleton *pSkel)
-{
-    if (mpkCurrentSkeleton != pSkel)
-    {
-        mpBoneTransformBuffer->BufferRange(pSkel->InverseBindMatricesData(), sizeof(CTransform4f) * 100, pSkel->InverseBindMatricesSize());
-        mpkCurrentSkeleton = pSkel;
-        mIdentityBoneTransforms = false;
-    }
-}
-
 void CGraphics::LoadIdentityBoneTransforms()
 {
-    static CTransform4f IdentityTransforms[200];
+    static const CTransform4f skIdentityTransforms[100];
 
     if (!mIdentityBoneTransforms)
     {
-        mpBoneTransformBuffer->Buffer(&IdentityTransforms);
+        mpBoneTransformBuffer->Buffer(&skIdentityTransforms);
-        mpkCurrentSkeleton = nullptr;
         mIdentityBoneTransforms = true;
     }
 }

src/Core/Render/CGraphics.h

@@ -29,9 +29,7 @@ class CGraphics
     static u32 mActiveContext;
     static bool mInitialized;
     static std::vector<CVertexArrayManager*> mVAMs;
-
     static bool mIdentityBoneTransforms;
-    static const CSkeleton *mpkCurrentSkeleton;
 
 public:
     // SMVPBlock
@@ -109,7 +107,6 @@ public:
     static void SetupAmbientColor();
     static void SetIdentityMVP();
     static void LoadBoneTransforms(const CBoneTransformData& rkData);
-    static void LoadBoneInverseBindTransforms(CSkeleton *pSkel);
     static void LoadIdentityBoneTransforms();
 };
 

src/Core/Resource/CSkeleton.cpp

@@ -29,6 +29,13 @@ void CBone::UpdateTransform(CBoneTransformData& rData, CAnimation *pAnim, float
 
     for (u32 iChild = 0; iChild < mChildren.size(); iChild++)
         mChildren[iChild]->UpdateTransform(rData, pAnim, Time, AnchorRoot);
+
+     rTransform *= mInvBind;
+}
+
+CVector3f CBone::TransformedPosition(const CBoneTransformData& rkData) const
+{
+    return rkData[mID] * AbsolutePosition();
 }
 
 bool CBone::IsRoot() const
@@ -84,12 +91,12 @@ void CSkeleton::Draw(FRenderOptions /*Options*/, const CBoneTransformData& rkDat
     for (u32 iBone = 0; iBone < mBones.size(); iBone++)
     {
         CBone *pBone = mBones[iBone];
-        const CTransform4f& rkBoneTransform = rkData[pBone->ID()];
+        CVector3f BonePos = pBone->TransformedPosition(rkData);
 
         // Draw bone
         CTransform4f Transform;
         Transform.Scale(skSphereRadius);
-        Transform.Translate(rkBoneTransform.ExtractTranslation());
+        Transform.Translate(BonePos);
         CGraphics::sMVPBlock.ModelMatrix = Transform;
         CGraphics::UpdateMVPBlock();
         CDrawUtil::DrawSphere(CColor::skWhite);
@@ -100,8 +107,8 @@ void CSkeleton::Draw(FRenderOptions /*Options*/, const CBoneTransformData& rkDat
 
         for (u32 iChild = 0; iChild < pBone->NumChildren(); iChild++)
         {
-            const CTransform4f& rkChildTransform = rkData[pBone->ChildByIndex(iChild)->ID()];
+            CVector3f ChildPos = pBone->ChildByIndex(iChild)->TransformedPosition(rkData);
-            CDrawUtil::DrawLine(rkBoneTransform.ExtractTranslation(), rkChildTransform.ExtractTranslation());
+            CDrawUtil::DrawLine(BonePos, ChildPos);
         }
     }
 }

src/Core/Resource/CSkeleton.h

@@ -19,7 +19,6 @@ class CSkeleton : public CResource
 
     CBone *mpRootBone;
     std::vector<CBone*> mBones;
-    std::vector<CTransform4f> mInvBindMatrices;
 
     static const float skSphereRadius;
 
@@ -34,9 +33,6 @@ public:
     std::pair<s32,float> RayIntersect(const CRay& rkRay, const CBoneTransformData& rkData);
 
     inline u32 NumBones() const                                         { return mBones.size(); }
-    inline const CTransform4f& BoneInverseBindMatrix(u32 BoneID) const  { return mInvBindMatrices[BoneID]; }
-    inline const void* InverseBindMatricesData() const                  { return mInvBindMatrices.data(); }
-    inline u32 InverseBindMatricesSize() const                          { return mInvBindMatrices.size() * sizeof(CTransform4f); }
 };
 
 class CBone
@@ -49,10 +45,12 @@ class CBone
     u32 mID;
     CVector3f mPosition;
     TString mName;
+    CTransform4f mInvBind;
 
 public:
     CBone(CSkeleton *pSkel);
     void UpdateTransform(CBoneTransformData& rData, CAnimation *pAnim, float Time, bool AnchorRoot);
+    CVector3f TransformedPosition(const CBoneTransformData& rkData) const;
     bool IsRoot() const;
 
     // Accessors
@@ -64,7 +62,6 @@ public:
     inline CVector3f Position() const                   { return mPosition; }
     inline CVector3f AbsolutePosition() const           { return mPosition + (mpParent ? mpParent->AbsolutePosition() : CVector3f::skZero); }
     inline TString Name() const                         { return mName; }
-    inline const CTransform4f& InverseBindMtx() const   { return mpSkeleton->BoneInverseBindMatrix(mID); }
 };
 
 #endif // CSKELETON_H

src/Core/Resource/Factory/CSkeletonLoader.cpp

@@ -14,12 +14,10 @@ void CSkeletonLoader::SetLocalBoneCoords(CBone *pBone)
 
 void CSkeletonLoader::CalculateBoneInverseBindMatrices()
 {
-    mpSkeleton->mInvBindMatrices.resize(mpSkeleton->MaxBoneID() + 1);
-
     for (u32 iBone = 0; iBone < mpSkeleton->mBones.size(); iBone++)
     {
         CBone *pBone = mpSkeleton->mBones[iBone];
-        mpSkeleton->mInvBindMatrices[pBone->ID()] = CTransform4f::TranslationMatrix(-pBone->AbsolutePosition());
+        pBone->mInvBind = CTransform4f::TranslationMatrix(-pBone->AbsolutePosition());
     }
 }
 

src/Core/Scene/CCharacterNode.cpp

@@ -73,7 +73,6 @@ void CCharacterNode::Draw(FRenderOptions Options, int ComponentIndex, const SVie
 
         // Draw surface OR draw entire model
         CGraphics::LoadBoneTransforms(mTransformData);
-        CGraphics::LoadBoneInverseBindTransforms(pSkel);
         CModel *pModel = mpCharacter->NodeModel(mActiveCharSet);
 
         if (ComponentIndex < 0)