seachnasaigh posted at 11:10PM Fri, 01 June 2018 - #4330972

My guess it that the offending diagonal rails were formed with n-gon sides; that would have a concave angle on the bottom, and Poser will display a concave n-gon by drawing a straight line from the bottom of one end to the bottom of the other end. So, for example, a Star of David n-gon will show as a hexagon.

That's exactly the issue. I thought I'd be clever and make each of the rails from a single object so it starts and ends parallel to the ground, but angles down to follow the slope of the stairs in the middle. I guess I'll have to do them as three separate objects.

Try exporting as an OBJ, if that option is available. The mesh must be UV-mapped to accept image map textures.