Surface orientation on imported solid breps rhino 7

Hello,
guess this is just a glitch in rhino 7 which will probably be resolved in one of the next updates, in any case for the record:
I’m experiencing weird issues with the orientation of surfaces on imported solids (from solidworks, both as .stp and .sldprt) in rhino 7.
First noticed this since we use a grasshopper definition to orient the largest surface of a brep on the xy plane and suddenly some objects ended up below zero.
Showing the backface color confirms this:


explode + join fixes this, but is not practical for multiple objects and deconstruct brep + join in grasshoper doesn’t seem to fix it reliably, checking for volume center < 0 and rotating them.

Do you have a sample you can post here?

I wouldn’t say this topic belongs in the Hardware category - I am going to move it to the Serengeti section.

Sorry for the wrong category, hier is the .sldprt and the rhino7 .3dm
dogbone_torture.3dm (165.7 KB) dogbone_torture.SLDPRT (131.9 KB)
initially thought it might be a solidworks issue, but rhino 6 seems to open it correct.

Ooh, yeah, that is interesting, it’s closed yet some of the surface normals are flipped… Explode/Join in normal Rhino fixes it but that definitely looks buggy. @chuck this may be in your wheelhouse…

Not me, but I’ll pass it on. Thanks.

RH-60639 Solidworks import has inconsistent normals

Hi All
Just wanted to mention, that I’m seeing this in V6 as well - but I guess that it’ll be fixed for V7 only. The parts are closed polysurfaces, but some normals are flipped - really weird! These were imported directly from a SWX assembly.
two parts imported from SWX.3dm (932.2 KB)
-Jakob

This happens from time to time with imported geometry, especially when naked or tolerant edges are involved, regardless of what version of Rhino is used (beginning from Rhino5).

Hi Jakob -

I suppose that if you have the original file, we could attach that to the YT item as an extra example.
-wim