public Brush Input { get; set; }
A System.Windows.Media.Brush that specifies the optional result of this effect. Default value is null (Nothing in VB).
You can use the Input property to specify a brush that will contain the result of applying this effect to accomplish tasks such as using a System.Windows.Media.Imaging.RenderTargetBitmap to cascade different shaders or save the result of the effect on an image.