iges-g — IGES Translator (IGES CSG to BRL-CAD)
iges-g [-X NMG_debug_flag] [-x rt_debug_flag] [-N solid_name] [-b ] [ -n | d | 3 | t ] -o database.g file.iges
iges-g
converts the specified
file.iges
to a BRL-CAD
database.g
file. The IGES file is expected to conform to IGES 5.1.
The
-n
option specifies that all rational B-spline surfaces in the IGES file should be
combined into one BRL-CAD spline solid.
The
-d
option indicates that IGES drawings should be converted to BRL-CAD NMG objects.
Theses objects will be two-dimensional drawings, not solids.
The
-3
option is the same as the
-d
option except the final projection into 2D is not performed. This may produce 3D drawings
in cases where the drawings have been produced from a 3D model.
The
-t
option requests all the trimmed surfaces in the IGES file be converted to
a single BRL-CAD NMG solid.
The
-N
option provides a name to be used for the single solid created under the
-n
or
-t
options, and is ignored for other options.
The
-p
option indicates that BREP objects should be converted to NMG solids rather than the default BOT solids.
The
-X
and
-x
options allow the setting of debug flags for the NMG routines and the rt library
respectively. See
nmg.h
and
raytrace.h
for details.
The absence of any of the
-n
,
-d
, or
-t
options results in the default behavior where
all IGES CSG and planar face BREP objects are converted to BRL-CAD
equivalents. Most conversions are exact, with the exceptions of the solid of
revolution and the solid of linear extrusion. These solids do not exist in BRL-CAD
and are therefore approximated. The solid of revolution is built from a series of
truncated right cones developed by approximating the curve to be revolved with a series
of straight line segments. The extrusion is similarly handled by approximating the
curve to be extruded with straight line segments and using that to build a BRL-CAD
polysolid.
Planar faced IGES BREP objects are converted to BRL-CAD NMG structures.
The Initial Graphics Exchange Specification (IGES) Version 5.1, IGES/PDES Organization, September 1991