Twinmotion/Datasmith materials issue with flipped/mirrored objects

[Enzo]

When exporting Datasmith to Twinmotion any mirrored or flipped object's material shows up incorrectly in Twinmotion when using 'Collapse by Material'. The workaround is to 'Keep Hierarchy' but for those of us who work with large models this is a massive inconvenience.
I'm sure the issue is with VWX not exporting normals correctly as mentioned many times before, but is there a way to control this process in a more efficient way?
Is there a way to 'convert' a flipped symbol or mirrored object so the normals maintain the correct orientation?

 

Thanks

[Neves+Creative Inc.]

I am having the same problem. I love using the mirror tool on large symmetrical projects. I tried exporting a big project last night and found half my project invisible because of the surface normals being reversed.😒

[Dave Donley]

When exported to Datasmith we mark materials double-sided, it sounds like the collapse by material doesn't work with double-sided materials.

[VIRTUALENVIRONS]

One of the ways to get speed in rendering and motion is to only have to deal with one side of a polygon, 'Backface Culling".   But, most programs just render both sides.  I assuming TM only wants one side by the sounds of it.

 

As Vectorworks is both a NURBS Solid and Surface modeller as well as Mesh, surface normals are probably a challenge.

 

If I need surface normals correct, I run that Vectorworks model into CINEMA 4D (C4D).  Activate Backface Culling so I can see (or not see) the offending polygons.  There are tools with C4D that can align thousands of polygons in one command.  A bonus if you use C4D, it can reduce the polygon count significantly while maintaining the correct hull.

Edited February 6 by VIRTUALENVIRONS

[AlanW]

Hi 

When you import to Twin Motion make sure you have double sided ticked. see attached