Embed 3D models (U3D) in PDF files using Ruby

#---------------------------------------------------------------------------------------
# Copyright (c) 2001-2023 by Apryse Software Inc. All Rights Reserved.
# Consult LICENSE.txt regarding license information.
#---------------------------------------------------------------------------------------

require '../../../PDFNetC/Lib/PDFNetRuby'
include PDFNetRuby
require '../../LicenseKey/RUBY/LicenseKey'

$stdout.sync = true

# Relative path to the folder containing the test files.
$input_path = "../../TestFiles/"
$output_path = "../../TestFiles/Output/"

def Create3DAnnotation(doc, 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.
	link_3D = doc.CreateIndirectDict
	link_3D.PutName("Subtype", "3D")
	
	# Annotation location on the page
	link_3D_rect = Rect.new(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.
	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).
	u3d_file = MappedFile.new($input_path + "dice.u3d")
	u3d_reader = FilterReader.new(u3d_file)
	
	u3d_data_dict = doc.CreateIndirectStream(u3d_reader, FlateEncode.new(Filter.new))
	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.
	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.
	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.
	ap_dict = link_3D.PutDict("AP")
	
	builder = ElementBuilder.new
	writer = ElementWriter.new
	writer.Begin(doc.GetSDFDoc)
	
	thumb_pathname = $input_path + "dice.jpg"
	image = Image.Create(doc.GetSDFDoc, thumb_pathname)
	writer.WritePlacedElement(builder.CreateImage(image, 0.0, 0.0, link_3D_rect.Width, link_3D_rect.Height))
	
	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)
end

	PDFNet.Initialize(PDFTronLicense.Key)
	
	doc = PDFDoc.new
	page = doc.PageCreate
	doc.PagePushBack(page)
	annots = doc.CreateIndirectArray
	page.GetSDFObj.Put("Annots", annots)
	
	Create3DAnnotation(doc, annots)
	doc.Save($output_path + "dice_u3d.pdf", SDFDoc::E_linearized)
	doc.Close
	PDFNet.Terminate
	puts "Done."