Adobe Acrobat SDK
Multimedia Features (Chapter 9 in PDF Reference)
Adobe® Supplement to the ISO 32000
9.5.6 Persistence of 3D Measurements and Markups 71
3D Radial Dimension
The
radial measurement
is used to define the radius or diameter of a circular 3D entity. The following figure
illustrates two examples of a radial dimension.
FIGURE 9.24
As shown on the left, the basic markup for a radial dimension consists of an arrow pointing to a circle or arc
that is connected to a leader line and text label that defines the radius or diameter. If the arrow is
positioned such that it is off the underlying arc, as in the figure on the right, an extension arc is generated
that clarifies which arc is being measured.
For radius measurements, the measure value is preceded by an “R” in the measure string. For diameter
values, the measure value is preceded by a Greek phi symbol (
).
In addition to the entries in
“TABLE 9.39a Entries in a 3D measurement/markup dictionary” on page 62
, the
following entries are defined for a 3D measurement dictionary with a
Subtype
value of
RD3
for 3D radial
measurement.
TABLE 9.39e Additional entries in a 3D measurement/markup dictionary
for a 3D radial dimension measurement
KEY
TYPE
VALUE
AP
array
(
Required; ExtensionLevel 3
) A three-element array of numbers specifying
the 3D annotation plane on which the measurement markup lies.
A1
array
(
Required; ExtensionLevel 3
) A three-element array of numbers specifying
the model space position of the first anchor point, called the circle
center point, in world space. It is assumed that this is a position on the
3D model associated with this view.
A2
array
(
Required; ExtensionLevel 3
) A three-element array of numbers specifying
the model space position of the second anchor point, which is a point
on the arc, in world space. It is assumed that this is a position on the 3D
model associated with this view.
N2
text string
(
Optional; ExtensionLevel 3
) The name of the part (or model tree node)
associated with anchor point 2 (
A2
). The part name is used to verify that
the part exists and is visible. If not, the measurement is not displayed. If
omitted, no validation occurs.
