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I startded to make an assimp only opengl skeletal animation demo. For that I used this: http://sourceforge.net/p/assimp/discussion/817654/thread/5462cbf5 And something is not correct in bone matrices. and my standerd bob_with_lamp model looks like this

and my standerd bob_with_lamp model(.md5) looks like this. its moving its parts but not in correct way.This is the code:

    for( size_t a = 0; a < anim->mNumChannels; ++a)
{
  const aiNodeAnim* channel = anim->mChannels[a];
  aiVector3D curPosition(0,0,0); 
  aiQuaternion curRotation(1,0,0,0);
  aiNode* targetNode = scene->mRootNode->FindNode(channel->mNodeName);
  while((int)time >channel->mNumPositionKeys) time-=channel->mNumPositionKeys;  
  curPosition = channel->mPositionKeys[(int)time].mValue;
  curRotation = channel->mRotationKeys[(int)time].mValue;
  aiMatrix4x4 trafo = aiMatrix4x4(curRotation.GetMatrix());
  trafo.a4 = curPosition.x; trafo.b4 = curPosition.y; trafo.c4 = curPosition.z;
  targetNode->mTransformation = trafo;
}
for (unsigned int n = 0; n < scene->mNumMeshes; ++n)
{
    const aiMesh* mesh = scene->mMeshes[n];
    std::vector<aiMatrix4x4> boneMatrices( mesh->mNumBones);
    for( size_t a = 0; a < mesh->mNumBones; a++)
    {
      const aiBone* bone = mesh->mBones[a];
      aiNode* node = scene->mRootNode->FindNode( bone->mName);
      boneMatrices[a] = bone->mOffsetMatrix;
      const aiNode* tempNode = node;
      while( tempNode)
      {
          aiMatrix4x4 m = tempNode->mTransformation;
          boneMatrices[a] *= tempNode->mTransformation;
          tempNode = tempNode->mParent;
      }
    }

and my render:

    std::vector<aiVector3D> resultPos( mesh->mNumVertices); 
    std::vector<aiVector3D> resultNorm( mesh->mNumVertices);

    for( size_t a = 0; a < mesh->mNumBones; ++a)
    {
      const aiBone* bone = mesh->mBones[a];
      const aiMatrix4x4& posTrafo = boneMatrices[a];
      aiMatrix3x3 normTrafo = aiMatrix3x3( posTrafo);
      for( size_t b = 0; b < bone->mNumWeights; ++b)
      {
        const aiVertexWeight& weight = bone->mWeights[b];
        size_t vertexId = weight.mVertexId; 
        const aiVector3D& srcPos = mesh->mVertices[vertexId];
        const aiVector3D& srcNorm = mesh->mNormals[vertexId];
        resultPos[vertexId] += weight.mWeight * (posTrafo *srcPos);
        resultNorm[vertexId] += weight.mWeight * (normTrafo * srcNorm);
      }
    }
    //And rendering the vertices from the pos vector

what should I change to made this to get correct positions?

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  • \$\begingroup\$ Does you bind pose look correct? \$\endgroup\$
    – Homar
    Commented Jul 19, 2014 at 4:36
  • \$\begingroup\$ Yes. It looks correct \$\endgroup\$
    – Csoki
    Commented Jul 19, 2014 at 9:22

1 Answer 1

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I have founded the solution: https://www.youtube.com/watch?v=xf0VD4ba4ns In this video's desc link shows a file that I used to the new code wich is working

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  • \$\begingroup\$ Cardinal internet sin: "I fixed it". I have the exact same problem, although this is hardly a solution. \$\endgroup\$
    – Yattabyte
    Commented Feb 18, 2016 at 6:23

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