View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0033318 | Community | OCCT:Data Exchange | public | 2023-01-17 01:57 | 2023-01-25 18:41 |
| Reporter | dpasukhi | Assigned To | ika | ||
| Priority | normal | Severity | major | ||
| Status | new | Resolution | open | ||
| Product Version | 7.7.0 | ||||
| Target Version | 7.8.0 | ||||
| Summary | 0033318: Data Exchange - Modifying the BRep flag after exporting the shape | ||||
| Description | https://dev.opencascade.org/content/differences-breptools-serializationdeserialization-75-76 [Regression] In my application I use BRepTools.Write() and BRepTools.Read() to serialize TopoDS_Shape instances to file. I have found some differences in the behavior of this method when upgrading from OpenCASCADE 7.5 to 7.6. I would expect that if I use BRepTools.Write/Read to serialize and deserialize objects to string as follows: shape_1 -> string_1 -> shape_2 -> string_2 then string_1 and string_2 would be equal. With OCCT 7.6, this fails on some shapes where OCCT 7.5 would pass. As an example, here is a snippet using the OCP bindings in Python.
def dump(shape):
b = io.BytesIO()
BRepTools.BRepTools.Write_s(shape, b)
return b.getvalue().decode('utf-8')
def load(s):
shape = TopoDS.TopoDS_Shape()
builder = BRep.BRep_Builder()
b = io.BytesIO(bytes(s, 'utf-8'))
BRepTools.BRepTools.Read_s(shape, b, builder)
return shape
pnt = gp.gp_Pnt(1, 0, 0)
shape_1 = BRepPrimAPI.BRepPrimAPI_MakeSphere(pnt, 1.0).Shape()
# serialize
ser_1 = dump(shape_1)
# deserialize
shape_2 = load(ser_1)
# serialize again
ser_2 = dump(shape_2)
with open('ser_1-7.5.3.txt', 'w') as f:
f.write(ser_1)
with open('ser_2-7.5.3.txt', 'w') as f:
f.write(ser_2)
# make sure serialization is the same
assert ser_1 == ser_2
With OCCT 7.5.3, ser_1 == ser_2, while with OCCT 7.6.3 ser_1 != ser_2. The difference is small - the "checked" bit of the shell entity is flipped. Is this expected? What is the significance of the "checked" bit? I also experience the same issue with BinTools, although it is harder to read the output. | ||||
| Tags | No tags attached. | ||||
| Test case number | |||||
