anchor.diff:        path.lineTo(secondVertexX, secondVertexY);
       }
       var z = 0.0;
  -    face.forEach((int x) {
  -      z += verticesToDraw[x - 1].z;
  +    face.forEach((dynamic x) {
  +      int xx = x;
  +      z += verticesToDraw[xx - 1].z;
       });
   
       path.close();
  
positive.code: 
      Vector3 vertex;
  
      lines.forEach((String line) {
        line = line.replaceAll(new RegExp(r"\s+$"), "");
        List<String> chars = line.split(" ");
  
        // vertex
        if (chars[0] == "v") {
  
negative.code:     _viewPortY = (size.height / 2).toDouble();
    }
  
    Map _parseObjString(String objString) {
      List vertices = <Vector3>[];
      List faces = <List<int>>[];
      List<int> face = [];
  