| |
CHCKEN |
| Equivalent PK functions: |
PK_BODY_check PK_FACE_check PK_FACE_check_pair PK_EDGE_check PK_GEOM_check PK_TRANSF_check |
CHCKEN ( entity, mxflts, nopts, option, faults, tags, pdata, nfault, ifail )
============================================================================
Checks an entity
Receives:
KI_tag_list_entity *entity --- entity (or pair of entities) to check
<KI_int_nitems> *mxflts --- maximum number of faults to return
<KI_int_nitems> *nopts --- number of option codes
KI_cod_chop option[nopts] --- array of option codes
Returns:
<KI_tag_list_int> *faults --- tokens describing faults in body
<KI_tag_list_<entity>> *tags --- faulty components
<KI_tag_list_<list>> *pdata --- list of data lists
<KI_int_nitems> *nfault --- number of faults returned
KI_cod_error *ifail --- failure indicator
Specific errors:
KI_unsuitable_entity unsuitable entity
KI_bad_option_data option inconsistent with type of entity
KI_list_wrong_length wrong number of items in entity list
KI_duplicate_list_item face appears twice in entity list
KI_not_in_same_body faces are not both from the same body
Description:
This function performs a series of checks on an entity, or a list of two
entities, and returns information about the faults found, if any. 'Entity'
may be a body, face, edge, a list of two faces from the same body, or any
geometric entity.
'nfault' gives the number of faults returned, and the lists 'faults',
'tags' and 'pdata' all contain 'nfault' elements. Information about each
fault is returned in corresponding positions in the three lists.
If there are no faults found, 'nfault' is zero, and no other information is
returned. Otherwise a token describing the fault is returned in 'faults',
and for some types of fault there will also be a tag of the faulty entity
in 'tags', and associated data in a list whose tag is in 'pdata'. 'pdata' is
a list of tags which may be : the tag of a list of 3 reals representing a
point; the tag of a list of tags ( of edges or vertices ) or the null tag.
If there is more than one fault in the entity then the function does not
guarantee to return all the faults.
The caller may set an upper limit on the number of faults found, in
'mxflts'; if 'mxflts' is zero, no limit is applied.
The options allow the caller to control which checks are performed; if
no options are supplied, all checks appropriate to the supplied entity will
be made. The following table details the options available.
token | meaning | applies to
-----------------------------------------------------------------------
| |
CHOPCR | check for corrupt data structure, and | bodies
| check identifiers |
| |
CHOPIG | check for invalid, self-intersecting, | all entities
| or degenerate geometry |
| |
CHOPPV | check for invalid, self-intersecting, | all entities
| or degenerate geometry, ignore results |
| of pre-V5 checks. |
| |
CHOPNO | check for invalid, self-intersecting, | all entities
| or degenerate geometry, ignore previous |
| checks and interface parameters. |
| |
CHOPED | check for inconsistencies between | topological entities
| topology and geometry of edges |
| |
CHOPFA | check for inconsistencies between | bodies and faces
| topology and geometry of faces |
| |
CHOPSX | check for self-intersecting faces | bodies and faces
| |
CHOPLC | check for loop consistency of faces | bodies and faces
| |
CHOPBX | check for size-box violations | topological entities
| |
CHOPFF | check for face-face inconsistencies | bodies and pairs of
| | faces
| |
CHOPSH | check for inside-out or inconsistent | bodies
| shells |
| |
The option CHOPIG will check for invalid, self-intersecting and degenerate
geometry, however the self-intersection checks are performed only if
the appropriate interface parameter is set ( see SEINTP ).
Geometry which passes these tests is marked so that the cost of these
tests need only be incurred once. Geometry which fails is also marked for
the same reason.
The option CHOPPV behaves just like CHOPIG, except that it forces a re-check
of geometry marked as valid by pre-V5 versions of Parasolid.
The option CHOPNO behaves just like CHOPIG, except that it always forces
a full check of the geometry, overriding the interface parameter,
even if the geometry has been marked as valid by a previous check.
When some types of check are omitted, an entity which would fail them may
produce misleading results or checker failures if checks which appear later
in the above table are applied. Very occasionally, checker failures
(denoted by tokens RTSTCF and RTSTFC, see table below) are caused by
difficult geometric configurations or the unexpected failure of an internal
numerical algorithm; such failures should not be taken to indicate that the
body is invalid.
The following table shows the tokens that may be returned, and the data
associated with them. For more details on these fault types and how they may
arise, see the chapter on 'Checking'.
token | meaning | associated tag | associated data
-----------------------------------------------------------------------
| | |
RTSTCR | data structure | null | null
| corrupt | |
| | |
RTSTID | invalid or duplicate| null | null
| identifiers | |
| | |
RTSTIG | invalid geometry | invalid geometric | null
| | entity |
| | |
RTSTGX | self-intersection | self-intersecting | point on the
| in geometry | geometric entity | self-intersection
| | |
RTSTDG | degenerate geometry | geometric entity | point from
| | | degenerate region
| | |
RTSTMG | missing geometry | topological entity | null
| | with no geometry |
| | |
RTSTOC | open or non- | edge | null
| periodic curve | |
| on ring edge | |
| | |
RTSTON | open or non- | edge | null
| periodic nominal | |
| geometry on ring | |
| edge | |
| | |
RTSTVC | vertex not on curve | edge | list of vertices
| | |
RTSTVN | vertex not on | edge | list of vertices
| nominal geometry | |
| | |
RTSTER | edge reversed | edge | null
| | |
RTSTRN | nominal geometry | edge | null
| in wrong direction | |
| for edge | |
| | |
RTSTSN | SP-curves of edge | edge | null
| not within edge | |
| tolerance of | |
| nominal geometry | |
| | |
RTSTSP | SP-curves of edge | edge | null
| not within edge | |
| tolerance | |
| | |
RTSTVT | vertices touch | edge | null
| | |
| | |
RTSTFO | faces incorrectly | edge | null
| ordered at edge | |
| | |
RTSTVS | vertex not on | face | list of vertices
| surface | |
| | |
RTSTES | edge not on surface | face | list of edges
| | |
RTSTEO | edges incorrectly | face | null
| ordered at vertex | |
| | |
RTSTMV | missing vertex at | face | point at
| surface singularity | | singularity
| | |
RTSTLC | loops inconsistent | face | null
| | |
RTSTSX | self-intersecting | face | point in region of
| face | | inconsistency
| (ie edge/edge | |
| inconsistency) | |
| | |
RTSTEF | wireframe edge/ | list of tags of | point in region of
| face inconsistency | the edge and face | inconsistency
| | |
RTSTEE | wireframe edge/ | list of tags of | point in region of
| wireframe edge | the pair of edges | inconsistency
| inconsistency | |
| | |
RTSTGC | geometry not G1 | face or edge | null
| continuous | |
| | |
RTSTBX | size box violation | face or edge | null
| | |
RTSTFF | face/face | list of tags of the | point in region of
| inconsistency | pair of faces | inconsistency
| | |
RTSTNG | body is inside out | body | null
| | |
RTSTSH | shells of region | region | null
| are inconsistent | |
| | |
RTSTRS | regions of body | body | null
| are inconsistent | |
| | |
RTSTSG | geometry/topology | shell | null
| inconsistency in | |
| shell | |
| | |
RTSTAC | acorn shell/shell | list of tags of | point in region of
| inconsistency | the pair of shells | inconsistency
| | |
RTSTCF | checker failure | topological entity | null
| | |
RTSTFC | failure during | list of tags of the | null
| face-face check | pair of faces |
Note that the tokens RTSTEF, RTSTFO, RTSTSG, RTSTAC can only occur for
general bodies.
There are special checks performed on B-curves and B-surfaces.
The restrictions on B-curves are:
i) A B-curve cannot have any first derivative of zero length.
ii) A B-curve cannot self-intersect.
iii) A B-curve cannot have a cusp interior to a segment.
iv) A B-curve must be at least position (G0) continuous.
The self intersection check in ii) is only performed if the appropriate
interface parameter is set (see SEINTP).
The restrictions on B-surfaces are:
i) A B-surface cannot contain any first derivative of zero length, except
at a legal degeneracy (defined below).
ii) A B-surface cannot self-intersect.
iii) A B-surface cannot have a ridge or a cusp interior to a patch.
iv) A B-surface must be at least position (G0) continuous.
v) A B-surface may meet itself in either the u or the v direction or both
to form a closed surface. If it does meet itself, it must do so all
along the boundary. It is illegal for for the surface to meet itself
at a single point.
vi) A legal degeneracy is one which occurs only on a boundary of the
surface, and which reduces all the boundary between two
or more knot values to a single point.
vii) A corner of a B-surface cannot be degenerate in both parameters.
The self intersection check in ii) is only performed if the appropriate
interface parameter is set (see SEINTP).
Offset surfaces whose underlying surfaces are B-surfaces are also checked for
self intersection only if the appropriate interface parameter is set (see
SEINTP).
SP-curves are also checked for self intersection only if the appropriate
interface parameter is set (see SEINTP).
If `entity' is a body, face, or edge and option CHOPFA or CHOPED is selected,
then additional checks on the geometry attached to 'entity' are performed.
The checks performed on curves attached to edges are:
i) The curve must be G1 continuous.
ii) If the curve is closed then it must have a periodic parameterisation.
The checks performed on surfaces attached to faces are:
iii) The surface must be G1 continuous.
iv) The constant parameter lines of the surface must be G1 continuous.
v) If the surface is closed in either direction then it must have a
periodic parameterisation in that direction.
vi) The surface may only contain degeneracies along one of its
boundaries if all of that boundary is degenerate.
Failure to pass these any of these checks will result in an RTSTGC code.
Checks i), iii), iv) and vi) are only performed if the appropriate interface
parameter is set - see SEINTP (SLIPCO).