Please enjoy the free license:

Username: for free
Company Name:

Use the "Unlock"-Button on the first page of the 3DPI to enter your registration. Watch out for case-sensitivity when entering the name and code.
License Benefits:
  • Immediately starting: The 3DPI will automatically go to the member-Tab after starting. There is no need to click on a Start-Button anymore. (version 3.6beta or heigher)
  • No registration reminder alert: The alert, that comes every 15 minutes reminding to register, will not appear anymore.

There are no other differences between the registered and unregistered version. Also with Director versions prior to 11, saving the w3d file is not possible even after registering the 3DPI, because Director does not offer a possibility to save it. Please read more about saving at 'Known Issues' and 'Docs - Saving a shockwave3D scene'.
Director 11 offers a possibility to save your 3D world, and with the help of the 3DPI it's even more simple.