Creating 3D models in other programs

CAD programs tend to render both sides of faces. For performance reasons games do not. This is very likely what you are seeing. It is just a matter of getting the faces pointing in the correct direction (by inverting faces where necessary). This is a common problem with moving models from modeling programs to games. 3DC gives you the option of not rendering both sides so that the model will look like it will in the game.

You can go ahead an use distance levels as long as they are used for more complicated objects. And of course there is that DirectX bug that causes the generation of distance levels to crash for merged objects.

Richard

I finally got to this. I loaded your original model and did see the effect you saw. A few faces were not visible but only from certain viewing angles. This indicates to me that it is a rendering error in MSTS.

I noticed that you exported distance levels, so I tried exporting your file without distance levels. This cured the problem. I am guessing that they have some sort of bug relating to individual faces (polygons) that are larger than the lowest distance level. Some of your faces were 200 meters long, and the lowest distance level is 100 meters.

Also, there isn’t likely much value in distance levels for simple structures. I would reserve distance levels (at least optmized ones) for objects with ]200 points.

Richard