OpenCascade Exception when Creating Grids

[kikootwo]

Hello,

If you have instantiated an IFCGRID type, and have not defined these lines:

#43= IFCDIMENSIONALEXPONENTS(1,0,0,0,0,0,0);
#44= IFCMEASUREWITHUNIT(IFCRATIOMEASURE(0.3048),#42);
#45= IFCCONVERSIONBASEDUNIT(#43,.LENGTHUNIT.,'FOOT',#44);

XbimXplorer will throw this exception

To recreate this bug, remove your reference to IFCCONVERSIONBASEDUNIT from unit assignment in any file with an IFCGRID. Please let me know if you need any additional information.

EDIT: Forgot to mention, the grid must have at least one grid axis.

[martin-loucka]

yes the same issue...

at BRepOffsetAPI_MakePipe.{ctor}(BRepOffsetAPI_MakePipe* , TopoDS_Wire* , TopoDS_Shape* )
at Xbim.Geometry.XbimGeometryCreator.CreateGrid(IIfcGrid grid)
at Xbim.ModelGeometry.Scene.Xbim3DModelContext.WriteShapeGeometries(XbimCreateContextHelper contextHelper, ReportProgressDelegate progDelegate, IGeometryStoreInitialiser geometryStore, XbimGeometryType geomStorageType) in c:\BuildAgent\work\860c3b913b6c647f\Xbim.ModelGeometry.Scene\Xbim3DModelContext.cs:line 1136
at Xbim.ModelGeometry.Scene.Xbim3DModelContext.CreateContext(ReportProgressDelegate progDelegate, Boolean adjustWcs) in c:\BuildAgent\work\860c3b913b6c647f\Xbim.ModelGeometry.Scene\Xbim3DModelContext.cs:line 676
at UnitTests.xBim.Readers.GeoReader.ReadGeo(String ifcFileName) in C:\01_Work\06_Senn\01_Code\99_Tests_UnitTests\xBim\Readers.cs:line 89

[andyward]

Do we have a test file to confirm this fix?

[SteveLockley]

kikootwo can you provide a file for this please. Just removing the Conversion based unit line seems odd, why do you want to do this? I suspect if you do so the units and the model precision will mismatch. i.e. The model will default to millimeters and everything will be approx 3 times smaller but you precision will still be the same.

[AllanCrow]

I am having the exact same issue with an IFC file. It loads with errors and warnings in Explorer but when in debug mode it crashes. The error is System.StackOverflowException

` var model = IfcStore.Open(dlgFileName);
if (model.GeometryStore.IsEmpty)
{
// Create the geometry using the XBIM GeometryEngine
try
{
var context = new Xbim3DModelContext(model);

                context.CreateContext(); //Crashes here <----------------------`

I have tried in XbimXplorer & Xbim.Presentation the following packages
Xbim.Geometry (5.1.430) & (5.1.403)
Xbim.Geometry.Engine.Interop (5.1.403) & (5.1.403)

I can share the IFC file if need be.

I have searched the Internet up and down and cannot find a solution!!!!

Please help.