occt: master 8574e329

Author Committer Branch Timestamp Parent
abv bugmaster master 2017-08-25 11:10:02 master 230b2bff
Changeset 0028968: Incorrect offset for the faces with singularities

Simple offset algorithm (BRepOffset_MakeSimpleOffset) is improved to handle the case when bspline surface has imprecise singularity at one of sides (when side is degenerated but not exactly to one point).
In such case, the algorithm tries to collapse all poles of singular side of the surface to the same point; this allows avoiding flapping of normal due to small fluctuations of surface.

If face being offset contains degenerated edges, then check for singularity is done using position and tolerance of corresponding vertices.
In addition, each side is checked with some user-defined tolerance (by default Precision::Confusion()); this helps to process cases when no edge is located at that side or if such edge is not encoded as degenerated.
New parameter Tolerance is introduced for that in BRepOffset_MakeSimpleOffset class.

Tests added:
bugs modelg_7 bug28968 - on isolated faces as reported in the issue, mostly for visual check (absence of loops)
offset simple F01-05 - on original shells, checking tolerances of resulting shell
mod - src/BRepOffset/BRepOffset.cxx Diff File
mod - src/BRepOffset/BRepOffset.hxx Diff File
mod - src/BRepOffset/BRepOffset_MakeSimpleOffset.cxx Diff File
mod - src/BRepOffset/BRepOffset_MakeSimpleOffset.hxx Diff File
mod - src/BRepOffset/BRepOffset_SimpleOffset.cxx Diff File
mod - src/BRepOffset/BRepOffset_SimpleOffset.hxx Diff File
mod - src/BRepTest/BRepTest_FeatureCommands.cxx Diff File
mod - src/BRepTest/BRepTest_OtherCommands.cxx Diff File
mod - src/DrawResources/CheckCommands.tcl Diff File
mod - src/ViewerTest/ViewerTest.cxx Diff File
add - tests/bugs/modalg_7/bug28968 Diff File
mod - tests/offset/simple/A04 Diff File
mod - tests/offset/simple/A11 Diff File
mod - tests/offset/simple/begin Diff File
mod - tests/offset/simple/end Diff File
add - tests/offset/simple/F01 Diff File
add - tests/offset/simple/F02 Diff File
add - tests/offset/simple/F03 Diff File
add - tests/offset/simple/F04 Diff File
add - tests/offset/simple/F05 Diff File