Represents the "3DV" entry of the external data dictionary used to markup 3d annotations object.

It is a required entry defined as part of the PDF 1.0 specification.

It contains a D3DViewElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 313, page 543.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 324, page 676.

The 3DV entry identifies the default view for the externally referenced 3D data, using the same format as the 3DV entry in the 3D annotation dictionary.