Faulty shapes with a fillet on a curved base, sweep, and a curve in the opposite direction

[pieterhijma]

Description

A model causes faulty shapes if it has a sweep with a curved base and at the end point of the sweep a curve in the opposite direction and a blend operation is performed on an edge of the sweep.

This issues follows on #690 that fixes the segfault but does not yet result in a correct shape.

Expected Behavior

A correct fillet without artifacts and "This shape seems to be valid" when doing checkshape.

Actual Behavior

Faulty shapes:

Faulty shapes as the following transcript shows:

$ DRAWEXE 
Draw[1]> Draw[2]> source curved-base-sweep-curve-opposite-dir.tcl
tolerance ang : 0.01
tolerance 3d  : 0.0001
tolerance 2d  : 1.0000000000000001e-05
fleche        : 0.001
tolblend 0.01 0.0001 1.0000000000000001e-05 0.001

Draw[3]> vdisplay result
Draw[4]> vfit
Draw[5]> vselmode 4 on
Draw[6]> vstate
Locally selected sub-shapes within result:
       Face #3

Draw[7]> checkshape result
On Shape faulty_1 :
BRepCheck_UnorientableShape
Shape faulty_2  on shape faulty_1 :
BRepCheck_NoCurveOnSurface
Shape faulty_3  on shape faulty_1 :
BRepCheck_NoCurveOnSurface

Faulty shapes in variables faulty_1 to faulty_3 

Sample Code or DRAW Tcl Script

The brep and DRAWEXE script are in curved-base-sweep-curve-opposite-dir.zip.

Operating System

Linux

Compiler

GCC

Bitness

64-bit

OCCT Version

latest

Additional Files

No response