g-vrml — Perform Boolean evaluations to produce a VRML version 2.0 file
g-vrml [-v ] [-d calc_dist_tol] [-a abs_tess_tol] [-n norm_tess_tol] [-r rel_tess_tol] [-x librt_debug_flag] [-X NMG_debug_flag] [-u units_name] [-o outfile] infile.g object(s)
g-vrml
performs the Boolean operations specified in any regions in the specified
object(s)
and writes the resulting NMG objects to
outfile
or to
stdout
if the
-o
option is not used. The output is in VRML version 2.0 format. The
-v
option requests verbose output while the conversion is taking place. The
-d
option specifies a calculational distance tolerance (in millimeters). This
tolerance is used to distinguish neighboring vertices. Any two vertices less than
this tolerance distance apart will be considered the same vertex. The default value
is 0.005mm.
Prior to performing the Boolean operations for each region, the involved primitive solids
are converted to a planar facetted approximation and stored as NMG solids. This tessellation
can be controlled using the tessellation tolerances. The
-a
option may be used to specify an absolute tessellation tolerance (in millimeters). This
requires that the maximum absolute error from the tessellated surface to the actual
surface must not be greater than
abs_tess_tol.
The
-n
option specifies a surface normal error tolerance (in degrees) for the tessellation.
The
-r
option may be used to set a relative error tolerance. This effectively
sets an absolute tolerance for each primitive solid by multiplying the
overall size of the solid by
rel_tess_tol.
The
-x
and
-X
options are used to set debug flags for
librt
and the
NMG
routines respectively. The definitions of these flags may be found in
raytrace.h
and
nmg.h.
The
-u
option can be used to set the units for the resulting VRML file (the default is mm).
Any units name that MGED accepts will work here.
The
-b
option provides BOT dump, and the
-e
option provides evaluation of all CSG and BOTs. They are mutually exclusive.