public static void Main() { // NOTE: // When used in trial mode, the library imposes some restrictions. // Please visit http://bitmiracle.com/pdf-library/trial-restrictions.aspx // for more information. const string PathToFile = "3dAnnotations.pdf"; using (var pdf = new PdfDocument()) { PdfPage page = pdf.Pages[0]; var bounds = new PdfRectangle(10, 80, 400, 400); Pdf3dAnnotation annot = page.Add3dAnnotation(bounds, @"..\Sample Data\dice.u3d"); annot.Activation.ActivationMode = PdfRichMediaActivationMode.OnPageOpen; pdf.Save(PathToFile); } Console.WriteLine($"The output is located in {Environment.CurrentDirectory}"); }