When creating a 3D pdf in Creo Elements Direct Modeling, you can measure on the 3D pdf in acrobat reader. Sometimes this is desired functionality, but sometimes, this is not desired, for example if you want to send this 3D pdf to a customer and you want to protect your intellectual property.
In the 3D pdf file type, it is possible to set a flag so you cannot measure on it. But currently, Modeling cannot set this flag to prevent measurement.
In the options of the “save – 3D pdf”, there should be added a setting “Allow measuring”