This has been an ongoing annoyance - When I model something in carrara and bring it into Poser there's always some polygons that turn dark - like a really dark greyscale. Sometimes it's like that for a whole object, sometimes just a single poly.

The model is perfect in carrara, there are no n-gons in the model, the uv map is fine with no stressed areas- yet when taken into poser I get the dark polygon/ dark object issue. It's like Poser is just flipping around certain things and not others.

Sometimes even when I take it into cinema 4d to ensure the polys are going in the same direction and then bring it into Poser, Poser still manages to read some polys as flipped. When I make polys two-sided Poser seems to crash, it's finicky to say the least.

Does anyone have experience with this?

Poser plain does not like two sided polys.

You can select "Normals Forward" for the materials in the Material Room.  It's on each root node. 

can you post a pic?

Thanks so much, SamTherapy!! That fixed it! :)

Normals forward is a fix that ideally should be fixed in the modeller.

I use Lightwave and have never had a problem with Poser flipping polygons. I do not use the import option though to make polygons consistant.

Polys can show black in Poser if they are not planar or if they are double sided.

Applying a small amount of bump will often fix co-planar polys.

If you can post a picture of the problem area , or send the mesh to someone who can check it people can give you better suggestions.

I use CInema for all my modeling and Riptide for all import/export, and I don't think I've had normals problems since my very first models.  Basically figure out what export option is screwing up your normals and note it, and never do that again ;)