Returns the bounding box for the given face.
Role: The default behavior of get_face_box is as follows:
If a bounding box already exists, it is returned.
If no bounding box exists, then a bounding box is calculated but it is not
guaranteed to be the tightest box available.
It is recommended that users call this function with the default values,
as ACIS has been optimised for this configuration. However, if a tight box
is required for spherical, toroidal or spline faces, the logical argument
tight_box may be set to TRUE. This may cause get_face_box to compute another
box, even if a bounding box already exists.
The default computation of a spherical face is governed by the option
tight_sphere_box. By default, this option is switched off. This means that
any spherical face box that is computed will be cached, and therefore an
explicit request for a tight spherical face box will force a computation.
If tight_sphere_box is switched on, then only tight spherical face
boxes will be computed (and cached). A box bounding the entire spherical
surface can be obtained through the SPHERE::make_box method.
The default computation of a toroidal face is governed by the option
tight_torus_box. By default, this option is switched on. This means that
only tight toroidal face boxes will be computed (and cached). A box bounding
the entire toroidal surface can be obtained through the TORUS::make_box method.
If tight_torus_box is switched off, then any toroidal face box that is
computed will be cached, and therefore an explicit request for a tight toroidal
face box will force a computation.
The default computation of a spline face is a tight box. Only tight boxes for
spline faces will be computed (and cached). This behaviour is fixed for
optimal performance of ACIS. A box bounding the entire spline surface can be
obtained through the SPLINE::make_box method.
ACIS has been configured to perform optimally with the default values for the
options tight_sphere_box and tight_torus_box. It is recommended that users do
not change these values, as the options will eventually be withdrawn. They
should not be changed mid-application. They should be set once at the
beginning of the session.
If untransformed_box is supplied, it will be expanded to include the
untransformed box of the face.
Effect: Changes model's derived data
Parameters:
this_face
face to examine
t
transform to apply to box
tight_box
flag to calculate tight box
untransformed_box
accumulating box
This object is included in the file: getbox.hxx
Copyright (c) 1989-2007 by Spatial Corp. All rights reserved.