Question about U3D Annotations (3D annotations in PDF)


I have some problems with my camera placement for u3d object.
In your sample there is these lines :

link_3D->Put("3DV", view3D_dict);
view3D_dict->Put("CO", new Number(27.5));

// A 12-element 3D transformation matrix that specifies a position and
// of the camera in world coordinates.
Obj* tr3d = new Array(12);
tr3d->PushBack(new Number(1));
view3D_dict->Put("C2W", tr3d);

In api help, i can't find any help about this: What words "xx" after
"Put("xx")" mean ?
Where can i find a complete documentation for the camera placement in
3d views for u3d object ?

'link_3D' and 'view3D_dict' are a SDF/Cos dictionary objects and the
sample code is illustrating how to populate dictionary with key/value

For example, the line:
  view3D_dict->Put("CO", new Number(27.5));
  (or view3D_dict->PutNumber("CO", 27.5) in PDFNet SDK 4.x)

inserts a new key/value pair to 'view3D_dict' dictionary object. The
first string ("CO") specifies that the associates value (i.e. 27.5)
represents the 'distance in the camera coordinate system along the Z
axis to the center of orbit for this view'. For a detailed description
of other key/value pairs in the 3D annotation dictionary, please refer
to the section 9.5.3 '3D Views' and TABLE 9.37 'Entries in a 3D view
dictionary' in PDF Reference Manual -

You may also want to read over PDFNet SDF/Cos tutorial for more
in-depth description of how to use the API: