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IDProjectCategoryView StatusDate SubmittedLast Update
0021413Open CASCADEOCCT:Modeling Algorithmspublic2009-10-15 10:352019-10-14 18:39
Reporterbugmaster Assigned Tomsv 
PrioritynormalSeveritytrivial 
Status assignedResolutionopen 
OSAll 
Summary0021413: Pipe fails - very sensitive to spine parameterization
Description1. Uncompress enclosed pipe-spine.zip. It contains two equal spines, only
differing in precision used when saving in the file (.ok used default 5 or 6
digits, .err - 17)
2. Use DRAWEXE:
Draw> tuya res.err dc1.err 1
Draw> tuya res.ok dc1.ok 1

In OK case the resulting B-Spline is a good pipe surface (Vdeg=5, Vknots=31)
while in ERR case there is some failure (Vdeg=11, Vknots=285). Failure is closer
to the end of the spine (extra twisting resulting in degree increase, etc).
Spine knots have dense distribution closer to the start - this likely
contributes to the failure. However sensitivity seems to high when default
tolerance of pipe algorithm is 1e-04 and knots and poles differ only in <1e-6 scale.

Additional post:

After some investigations I noticed that the issue is rather (or only?) in poles
- if to reduce precision (e.g. to modify *.err file leaving only 7 digits in
every pole coordinate) the algorithm works fine. So it seems like some precision
non-robustness.
I could add some work-around into my code to round up each coordinate to 7
digits on the fly but that would be the least I'd like to do. Ugly hack slowing
down the code, to say the least ...
TagsNo tags attached.
Test case numberbugs modalg_7 bug21413

Attached Files

  • pipe-spines.zip (43,841 bytes)

Activities

2009-10-15 10:35

 

pipe-spines.zip (43,841 bytes)

git

2017-06-28 18:03

administrator   ~0067782

Branch CR21413 has been created by apv.

SHA-1: f897957d0e8f6f8bec5a14098eaba3fde11e00ab


Detailed log of new commits:

Author: apv
Date: Wed Jun 28 18:03:25 2017 +0300

    0021413: Pipe fails - very sensitive to spine parameterization
    
    # Test case creation

apv

2017-06-28 18:05

tester   ~0067783

Dear BugMaster,

Please integrate branch CR21413 into the occt git-repository master.

After integration issue status should be changed to assigned. Responsible person is msv.

Issue History

Date Modified Username Field Change
2011-08-02 11:31 bugmaster Category OCCT:MOA => OCCT:Modeling Algorithms
2017-06-28 18:03 git Note Added: 0067782
2017-06-28 18:04 apv Assigned To bugmaster => apv
2017-06-28 18:04 apv Status new => feedback
2017-06-28 18:05 apv Note Added: 0067783
2017-06-28 18:05 apv Assigned To apv => bugmaster
2017-06-28 18:05 apv Status feedback => tested
2017-06-28 18:05 apv Test case number => bugs modalg_7 bug21413
2017-06-28 18:05 apv Fixed in Version EMPTY =>
2017-06-28 18:05 apv Description Updated
2017-06-30 12:03 apv Assigned To bugmaster => msv
2017-06-30 12:03 apv Status tested => assigned