3DS Max export - bones animation problem

Hi everyone!
I'm building a Direct3D based game engine.
I use my own file format for static / skinned meshes.
The exporter is based on an article from The Game Engine Architecture book and The NVidia nv-exporter sample (So it is the shader code).

My problem is that the bones I export do not "influence" properly the vertices, this way I get some strange skin deformations.

My approach was:
(I) In the exporter

• Export initial bone position and orientation (quaternion) in world space (flip z with y)
• For every frame (sample) - export bone position and orientation (quaternion) also in world space (flip z with y)(II) In the engine
  
  • Load initial bone position and orientation
    - D3DXMatrixRotationQuaternion(&mQ, &Q);
    - D3DXMatrixTranslate(&mT, &T);
    - D3DXMatrixMultiply(&matBone, &mQ, &mT);
    - D3DXMatrixInverse(&matInvBose, NULL, &matBone);
  • Update the bone's matrice based on the key and send to shader
    - The same as above except I don't invert matInvBone
    - Set the shader matrice as matBone * matInvBindPose
    This code decomposes the transform matrices and swaps Z with Y:
    
static void GetIGameTransform(Matrix3 m, geo::VERT3 &T, geo::VERT4 &Q)
{
m.NoScale();
AffineParts ap;
decomp_affine(m, ≈);

T.set(ap.t.x, ap.t.z, ap.t.y);
Q.set(ap.q.x, ap.q.z, ap.q.y, ap.q.w);
}

    
    This code gets the initial bone transform matrices:
    

// get initial bone matrix
for (int b = 0; b < boneIDs.Count(); b++)
{
// Get parent
...

// Get its transform matrix
GMatrix mat;
pSkin->GetInitBoneTM(pCurrent, mat);

geo::VERT4 Q;
geo::VERT3 T;
GetIGameTransform(mat.ExtractMatrix3(), T, Q);

SkeletonJoint* pJoint = new SkeletonJoint(name, parent, T, Q);
pSkeleton->AddJoint(pJoint);
}

    
    
    The following code exports bones animation:
    

geo::VERT3 T;
geo::VERT4 Q;

IGameNode * node = boneIDs[iNode]->pNode; // pSkin->GetIGameBone(vertex, bone);


GetIGameTransform(node->GetWorldTM(t).ExtractMatrix3(), T, Q);
pSQT->SetRotation(Q);
pSQT->SetTranslation(T);

pKey->AddSQT(pSQT);

    
    
    And the update code:
    

Skeleton* pSkeleton = m_pClip->GetSkeleton();
for (unsigned int i = 0; i < pSkeleton->m_joints.Count(); i++)
{
SkeletonJoint* pJoint = pSkeleton->m_joints;
AnimationPose* pAnimation = m_pClip->m_samples[m_iKey];
SQT* pSQT = pAnimation->m_jointPoses;
#ifndef EXPORTER
D3DXMATRIX matTmp, matT, matQ;
D3DXMatrixTranslation(&matT, pSQT->T.x, pSQT->T.y, pSQT->T.z);
D3DXMatrixRotationQuaternion(&matQ, &pSQT->Q);

matTmp = matQ * matT;
m_globalPoses = matTmp * pJoint->m_InvBindPose;

#endif
}

    
    
    The results:
    , when the initial bone matrice == animation matrice (M * M[sup]-1[/sup]=matrix identity)
    
    
    
    
    
    
    
    Thank you!