class ObjectModel
{
    public:
    ObjectModel();
    ObjectModel(string file);
    ~ObjectModel();
    ObjectModel& operator=(const ObjectModel &a)
    {
        NumVertex = a.NumVertex;
        NumNormal = a.NumNormal;
        NumTexCoord = a.NumTexCoord;
        NumTriangle = a.NumTriangle;
        VertexArray = a.VertexArray;
        NormalArray = a.NormalArray;
        TexCoordArray = a.TexCoordArray;
        TriangleArray = a.TriangleArray;
        Filename = a.Filename;
        return *this;
    }
    int NumVertex;
    int NumNormal;
    int NumTexCoord;
    int NumTriangle;
    ObjectVertex *VertexArray;
    ObjectNormal *NormalArray;
    ObjectTexCoord *TexCoordArray;
    ObjectTriangle *TriangleArray;
    string *Filename;
};

ObjectLoader::ObjectLoader(int objects)
{
    ObjectArray = new ObjectModel[objects];
    for(int a=0; a < objects; a++)
    {
        ObjectArray[a] = NULL; //Here
    }
}
//and
...
void ObjectLoader::LoadObject(int index)
{
    if(ObjectArray[index] != NULL) FreeObject(index); //Here
    ObjectArray[index] = new ObjectModel; //Here
    ReadData(index);
}