SECTION 9.5
829
3D Artwork
For example, these controls enable underlying nodes to be revealed, by making
the overlying nodes transparent or by moving them out of the way.
Note:
Do not confuse
nodes
with
view nodes.
A node is a PDF dictionary that spec-
ifies an area in 3D artwork, while a view node is a parameter in the 3D artwork
that specifies a view.
TABLE 9.47 Entries in a 3D node dictionary
KEY
TYPE
VALUE
Type
name
text string
(Optional)
The type of PDF object that this dictionary describes; if
present, must be
3DNode
for a 3D node dictionary.
(Required)
The name of the node being described by the node dic-
tionary. If the
Subtype
of the corresponding 3D Stream is
U3D
, this
entry corresponds to the field
Node block name
, as described in
the
Universal 3D file format
specification (see Bibliography). In the
future, nodes may be described using other 3D conventions.
Note:
When comparing this entry to node names for a particular con-
vention (such as Universal 3D), PDF viewer applications must trans-
late between the PDF text encoding used by PDF and the character
encoding specified in the 3D stream.
N
O
number
(Optional)
A number in the range [0, 1] indicating the opacity of
the geometry supplied by this node using a standard additive blend
mode.
If this entry is absent, the viewer should use the opacity specified
for the parent node or for the 3D artwork (in ascending order).
V
boolean
(Optional)
A flag indicating the visibility of this node. If
true
, then
the node is visible. If
false
, then the node is not visible.
If this entry is absent, the viewer should use the visibility specified
for the parent node or for the 3D artwork (in ascending order).
M
array
(Optional)
A 12-element 3D transformation matrix that specifies
the position and orientation of this node, relative to its parent, in
world coordinates (see Section 9.5.4, “Coordinate Systems for 3D).
The
N
entry specifies which node in the 3D stream corresponds to this node dic-
tionary.