HD07792: SHAPE DESIGN : PROBLEMS WHEN PARALLEL CURVES ARE CREATED IN A NURBS

APAR status

• Closed as suggestion for future release.

Error description

• Problem description:
  -------------------
  Catia V5 works with entities NURBS (Non Uniform Rational
  B-Spline). They are built through complex mathematics
  equations which define, accuracy, a curve or surface take
  into account several control points (which do not always
  belong to the trajectory) and some mass associated to these
  points.
  .
  When the NURBS surfaces are created, at the same time are
  created the Isoparametric Curves, which can be or not
  visible. If they are visible, it should not be a problem to
  work.
  .
  Unfortunately, for Catia V5 users, the isoparametric can be
  a serious problem when it work with NURB surfaces and
  wireframe intersection on it.
  .
  If we have a curve with 2 control points and one segment
  (visible), which has like support this type of surfaces and
  besides has isoparametrics on it, Catia V5 generates
  intersection points between isoparametrics and the curve;
  These points are called "Vertex".
  .
  These vertex spliced the starting curve according to the
  isoparametrics and some times, they forward gaps which could
  give problems in next steps.
  .
  This problem (vertex generation) make worse when are
  parallel curves on the surface. The vertex are multiply and
  the distance between gaps increase.
  .
  This problem impact, directly, in the model PLY generation
  for Composite process.
  .
  Sceanrio:
  --------
  1) Open the provided CATPart
  2) Select the Parallel curve icon
     Select the origin line as curve and reference surface as
  support
  3) Click OK
  .
  ===> wrong result:
  Different points display to the VERTEX (intersection between
  the lines and the isoparametrics)
  It is a problem in the Wireframe on Surfaces with
  Isoparametric Curves
  .
  

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

• THIS APAR IS CONSIDERED AS A SUGGESTION FOR IMPROVEMENT WHICH C
  ANNOT BE INCORPORATED IN VERSION 5 R12
  PLEASE CONTACT YOUR SUPPORT DEPARTMENT IN ORDER TO OPEN A REQUI
  REMENT FORM.
  .
  Incident Diagnosis
  Parallels having unuseful vertex points.
  .
  Development Request Justification :
  These vertex have already existed on the original curve. Mostly
  , they can be deleted but it requires extra developments which
  can be an impact too important on the CATIA software. The custo
  mer's problem is that there vertex points on a parallel curve o
  n a surface,  a the places other than the face edges.
  .
  Answer and By-Pass
  By-pass to make Parallel + Smooth (feature smooth and not paral
  lel with option smooth).
  .
  
  .
  

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

Applicable component levels