HelixWPF.MainViewModel.AddGroup C# (CSharp) Method

        public void AddGroup(List<int> selectedVertex)
        {
            MeshBuilder mesh = new MeshBuilder(false, false);
            foreach (int index in selectedVertex)
                mesh.AddSphere(this.Points[index], pointRaduis);
            var mesh1 = mesh.ToMesh(true);
            var redMaterial = MaterialHelper.CreateMaterial(Colors.Red);
            var insideMaterial = MaterialHelper.CreateMaterial(Colors.Yellow);
            
            // Add 3 models to the group (using the same mesh, that's why we had to freeze it)
            mg.Children.Add(new GeometryModel3D { Geometry = mesh1, Material = redMaterial, BackMaterial = insideMaterial });
        }
        public void AddGroup(bool canShowFace)

 private void Display(bool canShowObj)
 {
     MainViewModel mv = new MainViewModel();
     mv.AddGroup(canShowObj);
     if (selectedItemIndexes != null)
     {
         mv.AddGroup(selectedItemIndexes);
     }
     this.DataContext = mv;
 }