void UpdateRenderTarget(FrameworkElement fe)
{
RectangleF bounds = new RectangleF(0, 0, _vertsBounds.Size.Width, _vertsBounds.Size.Height);
fe.RenderToSurface(_visualSurface, new RenderContext(Matrix.Identity, Opacity, bounds, 1.0f));
// Unfortunately, brushes/brush effects are based on textures and cannot work with surfaces, so we need this additional copy step
GraphicsDevice.Device.StretchRectangle(
_visualSurface.Surface, new Rectangle(0, 0, _visualSurface.Size.Width, _visualSurface.Size.Height),
_visualTexture.Surface0, new Rectangle(0, 0, _visualTexture.Size.Width, _visualTexture.Size.Height),
TextureFilter.None);
}
