SECTION 9.5
793
3D Artwork
These options control whether annotations share the same run-time instance of
the artwork.
The
3DV
entry specifies the view of the 3D artwork that is displayed when the an-
notation is activated (as described in the next paragraph). 3D views, which are
described in Section 9.5.3, represent settings for the virtual camera, such as posi-
tion, orientation, and projection style. The view specified by
3DV
is one of the 3D
view dictionaries listed in the
VA
entry in a 3D stream (see Table 9.35).
The
3DA
entry is an activation dictionary (see Table 9.34) that determines how
the
state
of the annotation and its associated artwork can change. These states are
provided to delay the processing or display of 3D artwork until a user chooses to
interact with it. Such delays in activating 3D artwork can be advantageous to per-
formance.
3D annotations can be in one of two states:
•
Inactive
(the default initial state): the annotation displays the annotation’s nor-
mal appearance.
Note:
It is typical, though not required, for the normal appearance to be a pre-
rendered bitmap of the default view of the 3D artwork. Producers should provide
bitmaps of appropriate resolution for all intended uses of the document; for exam-
ple, a high-resolution bitmap for high-quality printing and a screen-resolution
bitmap for on-screen viewing. Optional content (see Section 4.10) can be used to
select the appropriate bitmap for each situation.
•
Active:
the annotation displays a rendering of the 3D artwork. This rendering is
specified by the annotation’s
3DV
entry.