The issue wasn't that the edges would turn themself back, like reset themselfs and you could visually see this, however it seemed turning edges had no effect on the rendered output with RTT. Sometime when i have time i can do a little test case and see if this is a real issue or something i am making up. On a side note it…
Its sort of a complex problem. It depends on a few things. Some apps it is essential, by default in max if you render with an un-triangulated mesh, you will get lots of smoothing errors as max randomly sets your invisible edges for you(regardless of any invisible edge tweaking you do, it will set them as it sees fit). From…