Embed 3D models (U3D) in PDF files using C++

//---------------------------------------------------------------------------------------
// Copyright (c) 2001-2023 by PDFTron Systems Inc. All Rights Reserved.
// Consult legal.txt regarding legal and license information.
//---------------------------------------------------------------------------------------

#include <PDF/PDFNet.h>
#include <PDF/PDFDoc.h>
#include <PDF/ElementWriter.h>
#include <PDF/ElementBuilder.h>
#include <SDF/Obj.h>
#include <Filters/MappedFile.h>
#include <Filters/FilterReader.h>
#include <Filters/FlateEncode.h>
#include <iostream>
#include "../../LicenseKey/CPP/LicenseKey.h"

using namespace pdftron;
using namespace Filters;
using namespace SDF;
using namespace PDF;
using namespace std;

std::string input_path =  "../../TestFiles/";

void Create3DAnnotation(PDFDoc& doc, Obj annots)
{
	// ---------------------------------------------------------------------------------
	// Create a 3D annotation based on U3D content. PDF 1.6 introduces the capability 
	// for collections of three-dimensional objects, such as those used by CAD software, 
	// to be embedded in PDF files.
	Obj link_3D = doc.CreateIndirectDict();
	link_3D.PutName("Subtype", "3D");

	// Annotation location on the page
	Rect link_3D_rect(25, 180, 585, 643);
	link_3D.PutRect("Rect", link_3D_rect.x1, link_3D_rect.y1,
		link_3D_rect.x2, link_3D_rect.y2);
	annots.PushBack(link_3D);

	// The 3DA entry is an activation dictionary (see Table 9.34 in the PDF Reference Manual) 
	// that determines how the state of the annotation and its associated artwork can change.
	Obj activation_dict_3D = link_3D.PutDict("3DA");

	// Set the annotation so that it is activated as soon as the page containing the 
	// annotation is opened. Other options are: PV (page view) and XA (explicit) activation.
	activation_dict_3D.PutName("A", "PO");  

	// Embed U3D Streams (3D Model/Artwork).
	{
		MappedFile u3d_file((input_path + "dice.u3d"));
		FilterReader u3d_reader(u3d_file);

		// To embed 3D stream without compression, you can omit the second parameter in CreateIndirectStream.
		Obj u3d_data_dict = doc.CreateIndirectStream(u3d_reader, FlateEncode(Filter()));
		u3d_data_dict.PutName("Subtype", "U3D");
		link_3D.Put("3DD", u3d_data_dict);
	}

	// Set the initial view of the 3D artwork that should be used when the annotation is activated.
	Obj view3D_dict = link_3D.PutDict("3DV");
	{
		view3D_dict.PutString("IN", "Unnamed");
		view3D_dict.PutString("XN", "Default");
		view3D_dict.PutName("MS", "M");
		view3D_dict.PutNumber("CO", 27.5);

		// A 12-element 3D transformation matrix that specifies a position and orientation 
		// of the camera in world coordinates.
		Obj tr3d = 	view3D_dict.PutArray("C2W"); 
		tr3d.PushBackNumber(1); tr3d.PushBackNumber(0); tr3d.PushBackNumber(0); 
		tr3d.PushBackNumber(0); tr3d.PushBackNumber(0); tr3d.PushBackNumber(-1);
		tr3d.PushBackNumber(0); tr3d.PushBackNumber(1); tr3d.PushBackNumber(0); 
		tr3d.PushBackNumber(0); tr3d.PushBackNumber(-27.5); tr3d.PushBackNumber(0);

	}

	// Create annotation appearance stream, a thumbnail which is used during printing or
	// in PDF processors that do not understand 3D data.
	Obj ap_dict = link_3D.PutDict("AP");
	{
		ElementBuilder builder;
		ElementWriter writer;
		writer.Begin(doc);

		std::string thumb_pathname(input_path + "dice.jpg");
		Image image = Image::Create(doc, thumb_pathname.c_str());
		writer.WritePlacedElement(builder.CreateImage(image, 0.0, 0.0, link_3D_rect.Width(), link_3D_rect.Height()));

		Obj normal_ap_stream = writer.End();
		normal_ap_stream.PutName("Subtype", "Form");
		normal_ap_stream.PutRect("BBox", 0, 0, link_3D_rect.Width(), link_3D_rect.Height());
		ap_dict.Put("N", normal_ap_stream);
	}
}

int main(int argc, char *argv[])
{
	int ret = 0;
	PDFNet::Initialize(LicenseKey);

	string output_path = "../../TestFiles/Output/";

	try  
	{	 
		PDFDoc doc;
		Page page = doc.PageCreate();
		doc.PagePushBack(page);
		Obj annots = doc.CreateIndirectArray();
		page.GetSDFObj().Put("Annots", annots);

		Create3DAnnotation(doc, annots);
		doc.Save((output_path + "dice_u3d.pdf").c_str(), SDFDoc::e_linearized, 0);
		cout << "Done" << endl;
	}
	catch(Common::Exception& e)
	{
		cout << e << endl;
		ret = 1;
	}
	catch(...)
	{
		cout << "Unknown Exception" << endl;
		ret = 1;
	}

	PDFNet::Terminate();
	return ret;
}