     
     private let _view: MTKView
     
-    private let _viewportOverlay: ViewportQuad
+    //private let _viewportOverlay: ViewportQuad
     
     private let _fontName = "HelveticaNeue"
     private let _fontSize: Float = 36

    }
    
    func mtkView(view: MTKView, drawableSizeWillChange size: CGSize) {
        _viewportOverlay.rectangle = BoundingRectangle(x: 20, y: 20, width: Double(size.width)/2-40, height: Double(size.height)/2-40)
        /*let scale = self.v!.backingScaleFactor
         let layerSize = view.bounds.size
         

        let options = CesiumOptions(
            clock: Clock(clockStep: .SystemClock, isUTC: false),
            imageryProvider: nil,
            terrain: false,
            lighting: false,
            skyBox: false,
            scene3DOnly: true
        )

        _globe = CesiumGlobe(view: _view, options: options)
        //_globe.scene.imageryLayers.addImageryProvider(BingMapsImageryProvider())
        _globe.scene.imageryLayers.addImageryProvider(TileCoordinateImageryProvider())
        
        _globe.scene.camera.constrainedAxis = Cartesian3.unitZ
        
