public void loadDataFromFile(String filename)
    {
        clearAllData();
        try{
            List<String> fileData = Files.readAllLines(Paths.get(filename), Charset.defaultCharset());
            
            for(String line : fileData){
                
                if(line.startsWith("v ")){
                    parseVertex(line);
                } else if (line.startsWith("vt ")){
                    parseUVCoord(line);
                } else if (line.startsWith("vn ")){
                    parseVertexNormal(line);
                } else if (line.startsWith("f ")){
                    parsePolygon(line);
                }
            }
        } catch(IOException ex) {
            System.out.println(ex.toString());
        }
    }