This device driver accepts Starbase function calls and encodes
acceptable 3-D display geometry into a special geometry metafile.
This archive file serves as an intermediate representation of Starbase
data destined to be rendered in the Personal Visualizer™
interactive environment. Additional processing by a support translator
must be performed before the information is suitable for the Personal
Visualizer™.
Functionality |
 |
The HP Starbase-to-Visualizer hpsbv
device driver is designed to facilitate data exportation from existing
Starbase applications to the Personal Visualizer™ or Advanced
Visualizer platform. Graphics code designed to display Starbase
geometry primitives (such as polygons) can be adapted to output
this information as an archive file which preserves the three dimensional
spatial relationships of the user's database. The information stored
in this file is then converted by a secondary translator (sbvtrans; for information
on this command, see the Starbase Reference)
into object data that is importable by the Personal Visualizer™.
The hpsbv
device driver functions as a virtual 3-D display device (with the
Personal Visualizer™ as the actual display). It captures
all view-independent matrix transformations to the archive file
while ignoring calls for view points, clipping planes, and display-dependent
information. Transformations normally associated with the interactive
viewing process are then reserved for use by the Personal Visualizer™.
The Starbase-to-Visualizer pipeline to the Personal Visualizer™
supports only geometry (polygons, spline surfaces, ellipses, etc.)
and geometric information (such as vertex normals). Attribute information
such as color, surface properties, and rendering-dependent data
are not accessible by the Personal Visualizer™. Using driver
specific graphics switches (gescape
functions), however, data organization in the archive can make color
specification in the Personal Visualizer™ nearly comparable
to rendering in a Starbase application. (See the gescape SBVESC_OBJ_NAME description
later in this chapter for more information about this approach.)
Object Definitions |
|
The Personal Visualizer™ deals with data as objects
in a 3-D environment. Objects are composed of one or more polygonal
faces. The result of translating an HPSBV archive file is one object
file containing all geometry collected by the graphics driver. The
name of this object is derived from the name of the archive unless
another is specified via a graphics escape. (Special gescapes can
be used to name multiple object definitions in the same output archive).
Printable version
