For all issues regarding the Forums use, please, refer to the Forum Rules.

Our Solutions

Need professional assistance?
Consider our:

Support Offerings

 

Need to speed up your development?
Have a look at our:

Samples & Tools

 

Need some functionality extending standard OCCT capabilities?
Check out our:

Adv. Components

Sewing two faces results in a very high tolerance

Timo Roth's picture
Forums: 

After sewing two faces, the result has a very high tolerance (20mm), although the faces look quite good to be sewed with a low tolerance. There are no holes between them.

Is it a sewing bug or are the given faces problematic?

DRAW-reproducer:

restore v.brep v
sewing r 0.3 v
tolerance r

The results are the same in OCC 6.5.2 - 6.5.4.

Kind regards,
Timo

Forum supervisor's picture

Dear Timo,
The specified high tolerance is not result of the sewing operation.
Your initial faces has this high tolerance:
Tolerance MAX=20.235956425969 AVG=4.0926465030034134 MIN=9.9999999999999995e-008
FACE : MAX=9.9999999999999995e-008 AVG=9.9999999999999995e-008 MIN=9.9999999999999995e-008
EDGE : MAX=20.235956425969 AVG=2.5542960296372641 MIN=9.9999999999999995e-008
VERTEX : MAX=20.235956425969 AVG=5.1176121398742014 MIN=1.0001000024999999e-007
So, try to check modeling steps of initial shapes.
Regards

Timo Roth's picture

Sorry, I added the wrong faces.
So, again.

After sewing the tolerance is now OK, but checkshape indicates a SameParameter error. So, I use fixshape to fix it, but the result has a tolerance of 20mm. I read that the SameParameter fix may increase the tolerance, but here it seems too much.

So, is it a fixshape bug or is the problem rather in sewing because it leads to the SameParameter error or are the given faces problematic?

DRAW-reproducer:

restore v.brep v
sewing r 0.3 v
tolerance r
checkshape r
fixshape f r
checkshape f
tolerance f

The results are the same in OCC 6.5.2 - 6.5.4.

Regards,
Timo

Forum supervisor's picture

Dear Timo,
If you need our technical support
you may contact us in usual way.
I do hope we will find acceptable solution for you.
Regards

Timo Roth's picture

The problem is not critical for us.
Therefore, I just wanted to report it and ask if it can be seen as a bug and if yes, in which area (sewing or fixShape). If it is a bug, I could create a Mantis-entry.

Regards,
Timo

SunHongLei's picture

hi,how do you sew two faces together ?

Timo Roth's picture

For sewing faces, you can use BRepBuilderAPI_Sewing but the result will be a shell, not a face. Normally, this is acceptable.

If the result should be a face, you might use BRepFeat_Gluer, but I have no experience with it.