And basically the resolution of the zbuffer that is used to track hidden surfaces by the video card has some effect on this all as well, and when you add more objects to the model the range of values that are used for the zbuffer will change, and so that's why you could see some differences in hidden surface display after you add an object.

Some of these kinds of things are just baked in to how 3D accelerated video cards are set up to work.

- Michael

Thanks for the thoughtful and clear answer. It is telling that when I see something strange in MOI I worry that it is an issue with my computer rather than the software. The model seems to behave perfectly with a tiny plane behind the model, and I am comforted to know that this is just an artifact.

Thanks again for your time.

You might want to make sure that individual objects are not using multiple styles. For instance, select an object and if it shows styles as "varies", then that could also attribute to the darker lines appearing more in the foreground of your display.

Michael T.