HC77610: WIREFRAME & SURFACES , SKETCHER PROBLEM : SPLITTING PART

APAR status

• Closed as suggestion for future release.

Error description

• 1st scenario:
  ------------
  1- Open model "Direction split surface.CATPart"
  "The model contains a surface of revolution (Revolute Surface)
  made from a sketch named Blue sketch? The main body is split by
  the surface.
  There is also another sketch (Red sketch).
  .
  2- Modify the part by changing the base sketch (Blue Sketch) of
  the surface of revolution (Revolute Surface) by the existing Red
  Sketch.
  .
  ==> Result: This is inverting the Splitting direction on the
  Main Body. The error is related to the direction of creation of
  the elements? Actually, profile in the Red Sketch were created
  from the bottom to the top and you can imagine that the profile
  in the Blue Sketch were created beginning from the top finishing
  at the bottom. Same kind of problem can be reproduced between
  profile that were created from left to right direction or right
  to left direction.
  .
  Conclusion: In a good user methodology it does not make sense to
  specify if profile has to be created in such or such direction.
  This problem can create design error when part modification
  occurs.
  .
  2nd scenario:
  ------------
  1- Open model "Direction offset profile.CATPart
  .
  "The model contains a green parallel curve, named parallel
  curve, made from a sketch named Blue sketch (elements are in
  Blue) note that the offset direction is at the left of the
  original Blue sketch? There is also another sketch named Red
  sketch (elements are in red).
  .
  2- Modify the Parallel curve by changing the Blue sketch for the
  red sketch.
  .
  Sketch. This is still related with the direction of creation of
  element where: Blue Sketch was created from the top to the
  bottom and the red sketch was created in the other direction
  (bottom to top) again you can reproduce this problem using
  left to right and right to left direction of creation.
  .
  Conclusion: It does not take much to create error when doing
  precision design. This is creating again a risk of error that
  would be easily avoided if this problem was not existing.
  .
  3rd scenario:
  ------------
  1- Open model "Direction with 3D elements.CATPart
  .
  "The model contains a sketch named White sketch: This sketch has
  two point at each extremities. There is one green point at the
  top of the profile and there is one red point at the end of the
  profile. Each of the point are followed by their respective 3D
  line that have the same color.
  The profile is close with two 3D curves (Blue ones).
  .
  2- Modify the White sketch by editing it. here are the steps to
  follow:
  .
  7 Double click on the White sketch in order to edit it
  7 Erase everything in this sketch
  7 Draw any line beginning from the bottom finishing at the top
  7 Exit your sketch and Update your design
  .
  ===> Result: the green line and point and Red line and point are
  now inverted (Red is on the top and Green is on the bottom). If
  you were creating your line from the top to the bottom the
  problem will not show.
  .
  Conclusion: Modifying a sketch is a day to day normal operation.
  In some case that can affect design radically. in wich direction
  to draw their lines and curves?
  .
                                           1- Open model "Directio
  n split line with a surface.CATPart"     .
                                           "The model contains a s
  plit green line named split line attachedto an offset plane (in
  red) and a surface of revolution named   Revolution Surface."
                                           .
                                           2- Modified the plane l
  ocation by editing it? here are the step to follow:
  
  .
  7 Double click on the Offset Plane (The red one)
  7 Click on on point located inside the revolute surface sketch
  (End of any element in this sketch)
  7 Hit ok
  .
  ===> Result: You can see that the Split line as been modified
  but the splitting direction is now inverted
  .
  The four problems are showing that element direction creation is
  very critical and that the algorithm currently used by the
  software can generate some critical design errors. It also
  created a huge loss of production because we have to verify
  modification over and over again and also makes a very bad
  sentiments in our user community where user are 'not trusting'
  the product because it can react in an unpredictable manner
  depending on how you proceed modifications to your part.
  .
  

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

• THIS APAR IS CONSIDERED AS A SUGGESTION FOR IMPROVEMENT FOR
  CATIA.
  PLEASE CONTACT YOUR SUPPORT DEPARTMENT IN ORDER TO OPEN A
  REQUIREMENT FORM.
  
   INCIDENT DIAGNOSIS:
  The stability criteria of the operator Split Shell by Wire is
  different when the Wire crosses an internal edge of the shell.
  .
   JUSTIFICATION FOR DEVLOPMENT REQUEST:
  The 3 first scenarios are a permanent restriction.
  About the 4th scenario, it is an enhancement request:
  A new calculation of the type of crossing between the shell and
  the wire has to be provided. Moreover, this code shall be
  versionned since it may change the result of the update of old
  CATIA V5 Parts
  .
   ANSWER AND POSSIBLE BY-PASS:
   In order to change the orientation of the result, edit the
  feature and select 'keep other side'.
  .
  

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