Thu, 01/17/2013 - 13:29
hi, I've been working with Open cascade for some time, mostly used with its geometry boolean apis.
Recently I've found a problem when cylinder generated by following codes will not be cutted correctly with BRepAlgoAPI_Cut
"
TopoDS_Shape cylinderSmall = BRepPrimAPI_MakeCylinder(gp_Ax2(gp_Pnt(-0.1212,0.98989,-0.213313),gp_Dir(1,0,1)),10,800);
TopoDS_Shape cylinderBig = BRepPrimAPI_MakeCylinder(gp_Ax2(gp_Pnt(-0.1212,0.98989,-0.213313),gp_Dir(1,0,1)),100,100);
//TopoDS_Shape ret = BRepAlgo_Cut(cylinderBig,cylinderSmall);
TopoDS_Shape ret = BRepAlgoAPI_Cut(cylinderBig,cylinderSmall);
return ret;
"
but the strange thing is BRepAlgo_Cut can work in this case.
I've tried to debug for a long time, but got no clue. Can you fix this or tell me how to work on it?
Fri, 01/18/2013 - 17:35
Dear kylin,
The case also is not reproducible in OCCT654 environment.
See below the script and attached result.
Draw[]> pload ALL
Draw[]> plane pln1 -0.1212 0.98989 -0.213313 1 0 1
Draw[]> pcyl cy1 pln1 10 800
Draw[]> pcyl cy2 pln1 100 100
Draw[]> fit
Draw[]> bop cy2 cy1
Draw[]> bopcut Result
Draw[]> fit
Draw[]> checkshape Result
## This shape seems to be valid
Draw[]> vdisplay Result
Draw[]> save Result Result24295.brep
Regards
Sat, 01/19/2013 - 15:12
Dear supervisor
I'm sorry, the code I've posted is not the code where error happened.
The error code is below. It was supposed that a hole should exist in the bigger cylinder, but there's none.（There's only a tiny difference of the parameters in the two codes.)
Draw[]> pload ALL
Draw[]> plane pln1 -0.1212 0.98989 -0.213313 1 0 1
Draw[]> plane pln2 -0.1212 0.98989 -0.213313 0.71111111 0 0.71111112
Draw[]> pcyl cy1 pln1 10 800
Draw[]> pcyl cy2 pln2 100 100
Draw[]> fit
Draw[]> bop cy2 cy1
Draw[]> bopcut Result
Draw[]> fit
Draw[]> checkshape Result
Draw[]> vdisplay Result
you can see, there's no hole in the cylinder but a small piece of circle in the bottom of the cylinder. This is the error I was talking about.
Thank you for your patience and your guide of the usage of the script tool.
Hope this would help.
Also there's a question, what should I do if I want to change the Precise value during the runtime?
Regards
Sat, 01/19/2013 - 15:16
The wrong result is attached. Thank you for your attention.
Mon, 01/21/2013 - 15:19
Dear kylin,
I would like to inform you that the posted problem (after your correction) has been checked and reproduced. The result contains Not Closed Shell.
I suggest you to register the issue in Mantis Bugtracker which is available via the Collaborative portal - http://dev.opencascade.org/index.php?q=home/get_involved.
If the problem is critical for you, you may contact us via the Contact Form http://www.opencascade.org/about/contacts/.
Regards
Sat, 01/26/2013 - 14:54
Dear supervisor
Thank you for your guidance, I'll go further until this be done.
Regards