HD39894: DMUOPT : OFFSET IS CREATED IN OPPOSITE DIRECTION IN DMU OPTIMIZ ER THAN IN GSD WORKBENSH.

APAR status

• Closed as Permanent restriction.

Error description

• DMUOpt : Offset Is Created in Opposite Direction in
  DMU Optimizer than in GSD workbensh.
  < Problem Summary >
  The problem is that the offset created in DMU
  Optimizer is in the opposite direction to the offset
  created in Generative Shape Design.
  .
  < Process >
  0) Start CATIA V5
  1) Open the CATProduct.
  Workbench : "DMU Optimizer".
  2) Double-click on the CATPart in the tree.
  ==> the CATPart is activated.
  3) Change the workbench to "GSD".
  4) Click on "Offset" command icon.
  ==> "Offset Definition" panel appears.
  5) Select the Surface to offset.
  ==> Keep the offset value of "10mm".
  6) Click on "OK" button.
  ==> "Offset.1" is created.
  ==> Note the offset direction.
  7) Click MB3 on "Offset.1".
  ==> Context menu appears.
  8) Select "Hide/Show" command from the menu.
  ==> "Offset.1" is in NoShow.
  9) Double-click on the top product in the tree.
  ==> Workbench switches back to "DMU Optimizer".
  10) Click on "Offset" command icon.
  ==> "Offset" panel appears.
  11) Click on "CATPart" in the tree.
  12) Change the offset value to "10mm".
  13) Click on "Save" button.
  ==> "Save As" panel appears.
  14) Keep the default name and click on "Save"
  button.
  ==> "OFFSET.cgr" is saved.
  15) Close all panels.
  16) Click MB3 on the top node in the tree.
  ==> Context menu appears.
  17) Select "Components" > "Existing component" in
  the menu.
  ==> "File Selection" appears.
  18) Select "OFFSET.cgr" and open the file.
  ==> The cgr file is added.
  19) Click MB3 on "Offset.1".
  ==> Context menu appears.
  20) Select "Hide/Show" command.
  ==> "Offset.1" is in Show.
  ==> Notice that the offset direction of cgr is
  opposite from the offset direction of GSD.
  >>> THIS IS THE PROBLEM ! <<<
  .
  < Actual Result >
  The offset direction of DMU Optimizer is opposite
  from the offset direction of GSD.
  .
  < Expected Result >
  The offset direction should be consistent in DMU
  Optimizer and GSD.
  .
  

Local fix

Problem summary

• DMUOpt : Offset Is Created in Opposite Direction in DMU Optimiz
  er than in GSD workbensh.
  DMUOpt : Offset Is Created in Opposite Direction in
  DMU Optimizer than in GSD workbensh.
  < Problem Summary >
  The problem is that the offset created in DMU
  Optimizer is in the opposite direction to the offset
  created in Generative Shape Design.
  .
  < Process >
  0) Start CATIA V5
  1) Open the CATProduct.
  Workbench : "DMU Optimizer".
  2) Double-click on the CATPart in the tree.
  ==> the CATPart is activated.
  3) Change the workbench to "GSD".
  4) Click on "Offset" command icon.
  ==> "Offset Definition" panel appears.
  5) Select the Surface to offset.
  ==> Keep the offset value of "10mm".
  6) Click on "OK" button.
  ==> "Offset.1" is created.
  ==> Note the offset direction.
  7) Click MB3 on "Offset.1".
  ==> Context menu appears.
  8) Select "Hide/Show" command from the menu.
  ==> "Offset.1" is in NoShow.
  9) Double-click on the top product in the tree.
  ==> Workbench switches back to "DMU Optimizer".
  10) Click on "Offset" command icon.
  ==> "Offset" panel appears.
  11) Click on "CATPart" in the tree.
  12) Change the offset value to "10mm".
  13) Click on "Save" button.
  ==> "Save As" panel appears.
  14) Keep the default name and click on "Save"
  button.
  ==> "OFFSET.cgr" is saved.
  15) Close all panels.
  16) Click MB3 on the top node in the tree.
  ==> Context menu appears.
  17) Select "Components" > "Existing component" in
  the menu.
  ==> "File Selection" appears.
  18) Select "OFFSET.cgr" and open the file.
  ==> The cgr file is added.
  19) Click MB3 on "Offset.1".
  ==> Context menu appears.
  20) Select "Hide/Show" command.
  ==> "Offset.1" is in Show.
  ==> Notice that the offset direction of cgr is
  opposite from the offset direction of GSD.
  >>> THIS IS THE PROBLEM ! <<<
  .
  < Actual Result >
  The offset direction of DMU Optimizer is opposite
  from the offset direction of GSD.
  .
  < Expected Result >
  The offset direction should be consistent in DMU
  Optimizer and GSD.
  .
  

Problem conclusion

• THIS PROBLEM IS PERMANENT RESTRICTION IN
  CATIA
  Incident Diagnosis
  DMUOpt : Offset Is Created in Opposite Direction in
  DMU Optimizer than in GSD workbensh.
  Restriction Explanation
  The GSD Offset command can use topological
  information to position the offset result, according
  to the surface topological normal.
  In the DMU Optimizer Offset command, only
  geometrical information can be used because this
  workbench has to deal with multi-CAD
  representations and generally no topological
  information is available, only geometrical ones.
  The thing is that the surface topological normal and
  the visualization normal are the opposite.
  In terms of topology, the normals have to point
  toward the inside of a solid whereas in the
  visualization world, normals have to point outside
  the solid. Otherwise, the faces will be considered as
  faces belonging to the inside of the solid and they
  won't therefore be rendered.
  In the visualization code, when we retrieve the
  topological information, we systematicaly revert
  the normal direction in order to display correctly
  the model. This operation is done on solids, but
  also on surfaces.
  That's why the topological normal and the
  visualization normal are the opposite and therefore
  why the two Offsets are not created in the same
  place.
  It could be possible to change the way we revert
  the topological normal to apply this operation on
  solids and not on faces. But impacts on the way
  objects are rendered is huge and we will also have
  to change the way we read all the previously saved
  files in order to know if we have to revert the
  normal direection or not - and this is not so obvious.
  By-Pass
  In the GSD Offset command, you can choose to
  reverse the normal direction and/or to select a
  negative value for the offset in order to create on
  the opposite side of the surface.
  .
  

Temporary fix

Comments

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