anchor.diff:  
           let buildings = ["Content/building1.jpg";"Content/building2.jpg";"Content/building3.jpg"]
           let material = new SCNMaterial ()
  -        material.Diffuse.Contents <- UIImage.FromFile (buildings.[rnd.Next(buildings.Length)])
  +        material.Diffuse.Contents <- texture buildings.[rnd.Next(buildings.Length)]
           material.Diffuse.ContentsTransform <- SCNMatrix4.Scale ( new SCNVector3(float32 width, float32 height, 1.F))
           material.Diffuse.WrapS <- SCNWrapMode.Repeat
           material.Diffuse.WrapT <- SCNWrapMode.Repeat
  
positive.code: [<Register("FSSceneKitViewController")>]
  type FSSceneKitViewController() = 
      inherit UIViewController()
  
      let building width length height (posx:nfloat) (posy:nfloat) (scene:SCNScene) (rnd:Random) =
          let boxNode = new SCNNode ()
  
negative.code: ﻿namespace SceneKitFSharp
   
  open System
  open System.Collections.Generic
  open System.IO
  open System.Linq
  open UIKit
  