Segfault. I am able to diagnose once i have a stack trace.. I was hoping you knew of a way to get a stacktrace from a segfault, but sounds like you end up diving into the source at that point...
thanks for the help, i know where to get the c++ source so i'll poke around... thanks as always for the quick response and help ! On Sun, Apr 18, 2010 at 7:54 AM, Thomas Paviot <tpav...@gmail.com> wrote: > What do you mean exactly with 'crash'? Do OCC raise an exception catched by > pythonOCC (like Standard_ConstructionError for instance) or is it a > segfault? > > If the error is not reproductible (ie. according to the wires passed to the > BRepOffsetAPI_MakeOffset class, the Perform() method passes or fails), it > may come from an issue in the algorithm used by OCC de perform the > operation. In that case, it's really difficult to identify the problem, > unless diving into the C++ code. > > Thomas > > 2010/4/18 Dave Cowden <dave.cow...@gmail.com> > >> Hi, Thomas, thanks! >> >> That definitely makes my code much more readable: but unfortunately the >> crash still occurs at that same place. I also switched to using Topo in a >> couple of other places ( where the face you see passed into that method is >> created ), but that did not help either. >> >> How do you go about finding what's going on when you encounter these? >> >> On Sun, Apr 18, 2010 at 12:30 AM, Thomas Paviot <tpav...@gmail.com>wrote: >> >>> 2010/4/18 Dave Cowden <dave.cow...@gmail.com> >>> >>> Hi, all: >>>> >>>> I'm struggling with a couple of problems that I presume to be null >>>> pointers that are crashing OCC. I have a feeling this may be related to >>>> memory management. >>>> >>>> For example, I've tracked down one crash to one line: >>>> BRepBuilderAPI_MakeOffset.Perform(). I load it with several wires, each >>>> of >>>> which I can display successfully immediately before invoking perform. Yet, >>>> Perform() crashes. See example below. I do not believe any object scoping >>>> issues are at play that I can see: all of the objects in question seem to >>>> be >>>> in scope when the crash happens. >>>> >>>> I am also fairly certain that its something I'm doing: all of the >>>> 'simple' test cases I create work fine. >>>> >>>> So my question is: are there any tricks/techniques I can use to isolate >>>> the problem when a crash occurs? Right now i'm using old school print >>>> statements to get to what method call dies, but I still cannot see what >>>> exactly is going wrong. Help is appreciated, this is completely kicking my >>>> butt :( >>>> >>>> >>>> #offset a face, returning the offset shape >>>> def _offsetFace(self,face,offset ): >>>> brt = BRepTools.BRepTools(); >>>> ow = brt.OuterWire(face); >>>> bo = BRepOffsetAPI.BRepOffsetAPI_MakeOffset(); >>>> >>>> bo.AddWire(ow); >>>> >>>> #now get the other wires >>>> te = TopExp.TopExp_Explorer(); >>>> te.Init(face,TopAbs.TopAbs_WIRE); >>>> while te.More(): >>>> w = ts.Wire(te.Current()); >>>> TestDisplay.display.showShape(w); # this line succesfully shows the >>>> wires on screen >>>> if not w.IsSame(ow): >>>> bo.AddWire(w); >>>> te.Next(); >>>> te.ReInit(); >>>> print "about to offset..."; >>>> >>>> bo.Perform(offset,0.00001); #this line crashes hard, but only >>>> sometimes. >>>> print "done offsetting.."; >>>> >>>> if not bo.IsDone(): >>>> raise Exception, "Offset Was Not Successful."; >>>> else: >>>> return bo.Shape(); >>>> >>>> >>> Hi Dave, >>> >>> If you want to traverse topology, I suggest you use the Topo class >>> available from the High-Level Topology subpackage (the 'Topo' name for this >>> class is maybe not the best one). This is a wrapper over the TopExp class >>> which fixes issues related to TopExp (with the use of the __hash__ method): >>> >>> from OCC.Utils.Topology import Topo >>> >>> #offset a face, returning the offset shape >>> def _offsetFace(self,face,offset ): >>> brt = BRepTools.BRepTools(); >>> ow = brt.OuterWire(face); >>> bo = BRepOffsetAPI.BRepOffsetAPI_MakeOffset(); >>> >>> bo.AddWire(ow); >>> >>> #now get the other wires >>> for w in Topo(face).wires(): >>> bo.AddWire(w); >>> print "about to offset..."; >>> >>> bo.Perform(offset,0.00001); >>> print "done offsetting.."; >>> >>> if not bo.IsDone(): >>> raise Exception, "Offset Was Not Successful."; >>> else: >>> return bo.Shape(); >>> >>> Hope this helps, >>> >>> Regards, >>> >>> Thomas >>> >>> >>> >>> _______________________________________________ >>> Pythonocc-users mailing list >>> Pythonocc-users@gna.org >>> https://mail.gna.org/listinfo/pythonocc-users >>> >>> >> >> _______________________________________________ >> Pythonocc-users mailing list >> Pythonocc-users@gna.org >> https://mail.gna.org/listinfo/pythonocc-users >> >> > > _______________________________________________ > Pythonocc-users mailing list > Pythonocc-users@gna.org > https://mail.gna.org/listinfo/pythonocc-users > >
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