I am trying to render a scene using sketch/hidden settings in NW Simulate 2013. I am getting diagonal lines on the surface of the wall, from the corner of a door to the corner of the wall (see attached image). The original model is a .dwg import using walls and doors drawn in AutoCAD MEP 2013.
To see if this issue is related to the DWG file, you could try creating a new DWG, draw a similar wall, and door, bring into Navisworks, and see if the same issue occurs.
If the issue does not show up, then you can compare the differences between the original file and the new one.
If the same issue occurs, it would be useful if you could attach the new (hopefully small) files, and include a description of the steps you are going through, so that we could try to reproduce what you are seeing.