Sometimes, exporting images isn't easy

UIKitExportEnv.cs

public class UIKitExportEnv : ExportEnv
{
	public UIKitExportEnv (string name, Model model)
		: base (name, model)
	{
	}
	
	protected override void WriteTexture (ITexture texture, ExportedFile file)
	{
		var width = texture.Width;
		var height = texture.Height;
		
		using (var imageContext = texture.CreateContext ())
		using (var image = imageContext.ToImage ())
		using (var renderContext = texture.CreateContextWithData (IntPtr.Zero)) {
					
			renderContext.TranslateCTM (0, height);
			renderContext.ScaleCTM (1, -1);
			renderContext.DrawImage (new RectangleF (0, 0, width, height), image);
			
			using (var render = renderContext.ToImage ())
			using (var uiImage = new UIImage (render))
			using (var data = uiImage.AsPNG ()) {
				unsafe {
					using (var s = new UnmanagedMemoryStream ((byte*)data.Bytes, data.Length)) {
						s.CopyTo (file.Stream);
					}
				}
			}
		}
	}
}