i have my matrix library setup as a column major, that is the 4th column contains the translation vector. now i am trying to do skinned mesh rotation, therefore implementing quaternions is required, or at least essential. now my problem is when i try to slerp between two quaternions. i believe that the problem is here based on the following information. mat4 rotation = rotateXYZ( PI, PI, PI ); quat q = matrixToQuat( rotation ); mat4 rotation2 = quatToMatrix( q ); now rotation = rotation2; ( this should be true, correct ) if i render the mesh, without trying to interpolate, the model is in bind pose position, so things are lining, translating properly. thanks for any help guys