Archived issue #0029699
Application Framework - OCAF ignores orientation of shape in TNaming
Description
The programmatic scenario is given in "Steps To Reproduce" section. Here is the overview:
Imagine you store a FORWARD face in OCAF using TNaming_Builder. Then imagine you reverse this face and store it again in the same attribute. Here is a bug: OCAF ignores the attempt to store the REVERSED face and keeps storing the FORWARD one.
I can imagine that TNaming_Builder::Generated() is not probably the best way to set shapes in OCAF (is there an alternative?). On the other hand, this problem is not reproduced for shapes with different TShape pointers (that is probably why we do not have this bug in parametric modelers).
Imagine you store a FORWARD face in OCAF using TNaming_Builder. Then imagine you reverse this face and store it again in the same attribute. Here is a bug: OCAF ignores the attempt to store the REVERSED face and keeps storing the FORWARD one.
I can imagine that TNaming_Builder::Generated() is not probably the best way to set shapes in OCAF (is there an alternative?). On the other hand, this problem is not reproduced for shapes with different TShape pointers (that is probably why we do not have this bug in parametric modelers).
Steps to reproduce
// Take any label, where doc is TDocStd_Document.
TDF_Label aDataLab = doc->Main();
// Create just any face.
TopoDS_Shape
face = BRepBuilderAPI_MakeFace( gp_Pln( gp::Origin(), gp::DZ() ) );
// Orientation is FORWARD initially.
std::cout << "Expected orientation: "
<< ( (face.Orientation() == TopAbs_FORWARD) ? "forward" : "reversed" ) << std::endl;
// Set shape.
doc->NewCommand();
{
TNaming_Builder aNBuilder(aDataLab);
aNBuilder.Generated(face);
}
doc->CommitCommand();
// Get shape to check its orientation.
Handle(TNaming_NamedShape) aShapeAttr;
aDataLab.FindAttribute(TNaming_NamedShape::GetID(), aShapeAttr);
face = aShapeAttr->Get();
// Orientation is forward (OK).
std::cout << "Orientation in OCAF: "
<< ( (face.Orientation() == TopAbs_FORWARD) ? "forward" : "reversed" ) << std::endl;
// Reverse shape before storing.
face.Reverse();
// Orientation is now REVERSED.
std::cout << "Expected orientation: "
<< ( (face.Orientation() == TopAbs_FORWARD) ? "forward" : "reversed" ) << std::endl;
// Set reversed shape.
doc->NewCommand();
{
TNaming_Builder aNBuilder(aDataLab);
aNBuilder.Generated(face);
}
doc->CommitCommand();
// Get shape to check orientation.
aDataLab.FindAttribute(TNaming_NamedShape::GetID(), aShapeAttr);
face = aShapeAttr->Get();
// BUG: Orientation is still forward, while it should be reversed (NOK).
std::cout << "Orientation in OCAF: "
<< ( (face.Orientation() == TopAbs_FORWARD) ? "forward" : "reversed" ) << std::endl;
TDF_Label aDataLab = doc->Main();
// Create just any face.
TopoDS_Shape
face = BRepBuilderAPI_MakeFace( gp_Pln( gp::Origin(), gp::DZ() ) );
// Orientation is FORWARD initially.
std::cout << "Expected orientation: "
<< ( (face.Orientation() == TopAbs_FORWARD) ? "forward" : "reversed" ) << std::endl;
// Set shape.
doc->NewCommand();
{
TNaming_Builder aNBuilder(aDataLab);
aNBuilder.Generated(face);
}
doc->CommitCommand();
// Get shape to check its orientation.
Handle(TNaming_NamedShape) aShapeAttr;
aDataLab.FindAttribute(TNaming_NamedShape::GetID(), aShapeAttr);
face = aShapeAttr->Get();
// Orientation is forward (OK).
std::cout << "Orientation in OCAF: "
<< ( (face.Orientation() == TopAbs_FORWARD) ? "forward" : "reversed" ) << std::endl;
// Reverse shape before storing.
face.Reverse();
// Orientation is now REVERSED.
std::cout << "Expected orientation: "
<< ( (face.Orientation() == TopAbs_FORWARD) ? "forward" : "reversed" ) << std::endl;
// Set reversed shape.
doc->NewCommand();
{
TNaming_Builder aNBuilder(aDataLab);
aNBuilder.Generated(face);
}
doc->CommitCommand();
// Get shape to check orientation.
aDataLab.FindAttribute(TNaming_NamedShape::GetID(), aShapeAttr);
face = aShapeAttr->Get();
// BUG: Orientation is still forward, while it should be reversed (NOK).
std::cout << "Orientation in OCAF: "
<< ( (face.Orientation() == TopAbs_FORWARD) ? "forward" : "reversed" ) << std::endl;
Public activity
7 archived notes
Participants are labeled by their role within this record.
This is known and norma behavior of the NamedShapeAttribute, since it keep all the shapes in the UsedShapes attribute, which contains the not-oriented shapes of map.
Ther naming mechanism never works with orientation of shapes and trying to make this map oriented map of shapes will casue huge number of regressions in the naming and in application that uses it.
So, I may only propose to use additional flag (or integer if FORWARD/REVERSED is not enough) attribute to keep the orientation of the shape, or create a new attribute, which will have no relation to the topological naming.
Ther naming mechanism never works with orientation of shapes and trying to make this map oriented map of shapes will casue huge number of regressions in the naming and in application that uses it.
So, I may only propose to use additional flag (or integer if FORWARD/REVERSED is not enough) attribute to keep the orientation of the shape, or create a new attribute, which will have no relation to the topological naming.
Mikhail, the described behavior is clearly inconsistent and may not be considered as normal. Please consider possible ways to fix it.
Sergey, is it help you if TDataXtd_Shape attribute (which stores the full shape only) will store the shape orientation, but not TNaming_NamedShape, which is related more to a local selection?
Mikhail, the issue is quite old and is already workarounded by deep copying a face whenever its orientation is reversed. It is up to you to decide whether and how to fix the reported inconsistency. I am sure that I had a look at TDataXtd_Shape as we did not really need the naming service. However I do not remember why it was not suitable (probably, it did not work well on undo/redo or anything else related to backup). Anyway, the issue deserves deeper investigation which I cannot conduct right now.
This is a principal idea of the topological naming algorithm, which can not be simply changed.
However it is already in TDataXtd_Shape, where the history naming structures are unused.
So, I would close this issue.
However it is already in TDataXtd_Shape, where the history naming structures are unused.
So, I would close this issue.
Dear Commenter 1,
No changes are needed, please, close this issue.
No changes are needed, please, close this issue.
Dear Commenter 1, could you close this issue.