Occasionally I accidentally stumble across something new (to me) in the APCD. When I do, the first thing I think of is to pass it on to others.
The reason I think it's new to me is because I've never seen it in any instructions or seen it discussed in the forums. Not so long ago I recall a discussion here in the forums on how to go about covering up the invisible side of a texture. As we all know, you can only see a texture from one side. If you look at it from the other side, it's completely invisible. I saw several suggestions about the best way to make a panel that is visible from both sides, but I never saw anyone suggest doing it the way I have stumbled across. If you guys don't know a sure-fire way to make a 3D object on plot that doesn't have any openings or seams in it, I'll be glad to make a little demonstration for you. I'm not going to take the time to do it if everyone already knows and I'm the last to find out. lol.
If you don't know it can be done, it's pretty neat. You can extrude pipes or posts or boxes, and complety close up all openings on all sides. With it created in that manner, you can't see though it from any direction. You get a totally enclosed hollow 3D object, like a basketball or a closed box, depending on how you shape the object.
If any of you guys don't know how, and would like to learn, let me know and I'll make a post on it. If everyone already knows, go ahead and point your finger at me and laugh. I'll get over it.
Dan
So it looks like you can't make double-sided faces with a triangle and then split any edges without it removing one side. 
At least you still have the option in video one...
Dan
Most any sharpened edges pulling at each other at sharp angles will most likely cause shadows. I don't see how this could be any different. But there are times when building objects in 3D that I have wanted to close off an open end of something, like hand railings or other items that may be visible on the course. This is perfect for things like that.