private void InitializeCompositionVariables() { var bounds = ApplicationView.GetForCurrentView().VisibleBounds; var maxWindowWidth = bounds.Width.ToFloat(); var maxWindowHeight = bounds.Height.ToFloat(); var maxWindowRadius = Math.Max(maxWindowWidth, maxWindowHeight); // Setup sky visual's size, position, opacity, etc. _skyVisual = Sky.ContainerVisual(); _skyVisual.Size = new Vector2(maxWindowRadius * SkyVisualAreaRatio); _skyVisual.Offset = new Vector3(-SkyVisualRadius + maxWindowWidth / 2.0f, -SkyVisualRadius + maxWindowHeight / 2.0f, 0.0f); _skyVisual.CenterPoint = new Vector3(SkyVisualRadius, SkyVisualRadius, 0.0f); _skyVisual.Opacity = 0; _compositor = _skyVisual.Compositor; _reading = _compositor.CreatePropertySet(); _reading.InsertVector3("Offset", new Vector3(0.0f, 0.0f, 0.0f)); _imageLoader = ImageLoaderFactory.CreateImageLoader(_compositor); _circleBrush = _compositor.CreateSurfaceBrush(); _circleBrush.Surface = _imageLoader.LoadImageFromUri(new Uri(StarUriString)); if (_inclinometer != null) { SetupSkyVisualOffsetExpressionAnimation(); } }