CHAPTER 9
792
Multimedia Features
KEY
TYPE
VALUE
3DI
boolean
(Optional)
A flag indicating the primary use of the 3D annotation. If
true
, it is
intended to be interactive; if
false
, it is intended to be manipulated programmat-
ically, as with a JavaScript animation. Viewer applications may present different
user interface controls for interactive 3D annotations (for example, to rotate,
pan, or zoom the artwork) than for those managed by a script or other mecha-
nism.
Default value:
true
.
3DB
rectangle
(Optional)
The 3D view box, which is the rectangular area in which the 3D art-
work is to be drawn. It must be within the rectangle specified by the annotation’s
Rect
entry and is expressed in the annotation’s target coordinate system (see be-
low).
Default value: the annotation’s
Rect
entry, expressed in the target coordinate sys-
tem. This value is
[ -w/2 -h/2
w/2 h/2
]
, where
w
and
h
are the width and height,
respectively, of
Rect
.
The
3DB
entry specifies the
3D view box,
a rectangle in which the 3D artwork ap-
pears. The view box must fit within the annotation’s rectangle (specified by its
Rect
entry). It may be the same size, or it may be smaller if necessary to provide
extra drawing area for additional 2D graphics within the annotation.
Note:
Although 3D artwork can internally specify viewport size, PDF consumer ap-
plications ignore it in favor of information provided by the
3DB
entry.
The view box is not specified in the same coordinate system as the annotation’s
rectangle, but rather in the annotation’s
target coordinate system,
whose origin is
at the center of the annotation’s rectangle. Units in this coordinate system are the
same as default user space units. Therefore, the coordinates of the annotation’s
rectangle in the target coordinate system are
[ -
w
/2 -
h
/2
w
/2
h
/2 ]
given
w
and
h
as the rectangle’s width and height.
The
3DD
entry specifies a 3D stream that contains the 3D artwork to be shown in
the annotation; 3D streams are described in Section 9.5.2. The
3DD
entry can
specify a 3D stream directly; it can also specify a 3D stream indirectly by means
of a 3D reference dictionary (see “3D Reference Dictionaries” on page 801).