Represents the "V" entry of the go-to-3d-view action object.

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

This property may contain one of four different types:.

1) An integer representing a PDF numeric object.

2) A string representing a PDF name object.

This item may take one of the following valid values:.

• F
• L
• N
• P
• D

3) A string representing a PDF string object.

4) A D3DViewElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 216, page 429.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 220, page 522.