add 3d object

Do you want to do this on the desktop using Acrobat as the runtime? If so, you'd need to write a plugin and as long as the process is triggered by a user, there should be no licensing issues.

If you want the conversion to happen on the server or otherwise automated, you won't be able to use Acrobat because it's not licensed that way. In that case, you'd want to use something like the Datalogics PDF Java Toolkit. I have a blog post about creating 3D PDF at the URL below. The Datalogics PDF Java Toolkit is Adobe technology licensed and sold by Datalogics.

You could optionally use the Adobe PDF Library, also available through Datalogics but the code may be a bit more complicated.

http://blogs.datalogics.com/2016/01/27/creating-3d-pdf-files-using-the-datalogics-pdf-java-toolkit/

J-